Mini Tools Collection
Useful one-page tools for real work
ToolPatch is a growing collection of focused utilities. Each page handles one task with clear inputs, fast results, and practical outputs.
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Marine & Navigation
Featured
Anchor Scope & Holding Calculator
Check required scope and estimate holding confidence for anchoring setup.
Evaluate anchoring setup with depth, bow height, deployed rode, wind, and bottom type. Useful for anchorage planning to confirm scope requirements and identify higher-risk holding conditions.
Conversion Tools
Featured
Angle Converter
Convert angles between deg, rad, and grad.
Convert angular units for math, engineering, and graphics workflows.
Finance
Featured
Annuity Payment Calculator
Calculate monthly loan payment, total paid, and interest.
Estimate annuity-style payment schedules for mortgages, auto loans, and other fixed-term debt.
Statistics
Featured
ANOVA One Way Calculator
Run one-way ANOVA summary statistics for multiple groups.
Compute sums of squares, mean squares, and F statistic for one-factor group comparisons.
Developer
Featured
API Response Formatter
Beautify and syntax highlight JSON/XML responses.
Format API responses with syntax highlighting, size stats, and copy functionality.
Design & Branding
Featured
Background Remover
Remove image backgrounds locally in-browser with color keying.
Upload an image, pick a background key color, tune tolerance/softness, and download transparent PNG output.
Data
Featured
Bar Chart Generator
Create bar charts from labeled values and compare categories at a glance.
Paste labeled values and generate a horizontal bar chart with totals, relative bar lengths, and percentages.
Developer Tools
Featured
Barcode Generator
Generate CODE39 and EAN-13 barcodes as SVG output.
Barcode Generator creates scan-ready SVG barcodes for CODE39 and EAN-13 directly in the browser workflow. It is useful for inventory labels, internal IDs, packaging mockups, and test fixtures where you need deterministic machine-readable output. The tool validates format-specific input, auto-calculates EAN-13 check digits for 12-digit payloads, and surfaces clear errors when content is invalid. You can control module width and bar height to tune readability for printers and scanners. Use this for practical operational output; confirm print quality and scanner compatibility before production rollouts.
Solar & Power
Featured
Battery Bank Capacity Calculator
Calculate required usable and total battery capacity.
Calculate battery bank size in kWh and Ah based on autonomy days, voltage, and depth of discharge.
Statistics
Featured
Bayes Theorem Calculator
Compute posterior probability from prior, sensitivity, and false positive rate.
Useful for medical test interpretation, risk scoring, and signal-detection decisions.
Physics
Featured
Blackbody Radiation Calculator
Calculate Wien peak wavelength and Stefan-Boltzmann radiation power.
Estimate blackbody spectral peak and total emitted power from temperature and emitting area.
Health & Fitness
Featured
BMI Calculator
Compute body mass index from weight and height with category classification.
Enter weight and height to calculate BMI and identify general weight status bands. Useful for quick health tracking and baseline fitness planning.
Health & Fitness
Featured
Body Fat Estimator
Estimate body fat percentage from body measurements.
Uses circumference-based formulas for quick body composition estimates.
Chemistry
Featured
Boyle's Law Calculator
Calculate gas pressure and volume relationships at constant temperature.
Apply Boyle's Law (P₁V₁ = P₂V₂) to solve for unknown pressure or volume. Enter any 3 values to calculate the 4th.
Business
Featured
Break-Even Analysis Calculator
Calculate break-even point and contribution margin.
Determine break-even units and revenue using fixed costs, variable costs, and pricing.
Business
Featured
Break-Even Calculator
Calculate break-even units and revenue with fixed and variable cost inputs.
Understand exactly how many units you need to sell to cover costs and when you start generating profit. Enter fixed costs, variable cost per unit, and price per unit. Add a target profit to estimate your next milestone.
Data
Featured
Bubble Chart Generator
Create bubble charts from x, y, and size values.
Paste labeled x/y/size rows and generate a bubble plot to compare position and magnitude together.
Project Management
Featured
Burndown Forecast Calculator
Forecast sprint completion date from current burn rate.
Estimate whether your sprint is on track and what burn rate is needed to finish remaining scope on time.
Finance
Featured
CAGR Calculator
Calculate compound annual growth rate between two values over time.
Use CAGR to compare investment or revenue growth trends consistently over multiple years.
Text Tools
Featured
Case Converter
Convert text between different cases.
Convert text to UPPERCASE, lowercase, Title Case, camelCase, snake_case, and kebab-case with individual copy buttons.
Finance
Featured
Cash Runway Calculator
Estimate startup runway and projected cash balance over time.
Forecast how long your current cash lasts based on burn rate, revenue, and growth assumptions. This tool helps founders and finance leads model survival scenarios and plan fundraising or cost adjustments with clear time-based outputs.
Solar & Power
Featured
Charge Controller Sizing Calculator
Size MPPT or PWM charge controllers for safe operation.
Calculate required controller current (Amps) based on PV power and battery voltage with safety margins.
Chemistry
Featured
Charles' Law Calculator
Calculate gas volume and temperature relationships at constant pressure.
Apply Charles' Law (V₁/T₁ = V₂/T₂) to solve for unknown volume or temperature. Automatically converts Celsius to Kelvin.
Business
Featured
Churn Impact Simulator
Project customer count and MRR under churn and acquisition assumptions.
Model how churn and new customer acquisition affect your customer base and recurring revenue over 12 months. Useful for SaaS operators prioritizing retention initiatives and board-level planning.
Network
Featured
CIDR Aggregator
Compute a covering supernet for multiple CIDR blocks.
Summarize multiple routes into a single supernet to simplify route tables and policy logic.
Design & Branding
Featured
Color Palette Generator
Create color palettes from a base color and harmony scheme.
Generate analogous, complementary, triadic, and monochrome palettes with exportable hex codes.
Marine & Navigation
Featured
COLREGs Encounter Classifier
Classify head-on, crossing, or overtaking geometry from bearing/course data.
Provide quick encounter classification from own course, target course, and relative bearing. Useful for training and bridge-team scenario review. Output is advisory only and should never replace proper COLREGs application and lookout.
Finance
Featured
Compound Interest Calculator
Forecast investment growth with compounding and recurring contributions.
Estimate how savings and investments can grow over time using compound interest. Enter your starting amount, expected annual return, time horizon, compounding frequency, and optional yearly contributions. This calculator helps freelancers, families, and founders run fast scenarios without opening a spreadsheet. Use it to compare contribution plans, test different return assumptions, and set realistic long-term targets. Tip: run conservative, expected, and aggressive scenarios to understand a full range of outcomes before making financial decisions.
Statistics
Featured
Confidence Interval Calculator
Estimate confidence intervals from mean, standard deviation, and sample size.
Calculate margin of error and confidence bounds for common confidence levels. Great for analysis reports, A/B test summaries, and classroom statistics.
Statistics
Featured
Confidence Level Z Value Tool
Convert confidence levels to z critical values and margin of error.
Get z* for common and custom confidence levels and estimate margin of error with sigma and n.
Business
Featured
Conversion Rate Calculator
Calculate conversion rate, AOV, and revenue per visitor.
Analyze website performance with conversion rate, average order value, and revenue per visitor metrics.
Conversion Tools
Featured
Cooking Measurements Converter
Convert kitchen volume units like tsp, tbsp, cups, ounces, pints, and liters.
Convert common cooking measurement units with quick equivalents for recipe scaling and prep.
Marine & Navigation
Featured
CPA/TCPA Risk Calculator
Compute closest point of approach and time to CPA with risk banding.
Calculate CPA and TCPA from ownship and target kinematics using relative motion vectors. Useful for watchstanding support and collision-risk triage when evaluating multiple contacts.
Developer Tools
Featured
Cron Builder
Build cron expressions and ready-to-paste crontab lines from schedule fields.
Set minute/hour/day fields and generate cron expressions with command output for scheduling jobs.
Developer
Featured
CSS Minifier/Beautifier
Minify or beautify CSS code.
Minify CSS for production or beautify for readability with size comparison and copy functionality.
Business
Featured
Customer Lifetime Value Calculator
Calculate total customer value over their lifetime.
Compute CLV from average purchase value, frequency, and customer lifespan.
Math
Featured
Cylinder Volume Calculator
Calculate cylinder volume and surface area from radius and height.
Compute volume, total surface area, lateral area, and base area from cylinder dimensions.
Physics
Featured
Damped Oscillator Calculator
Solve damped spring-mass response and classify damping regime.
Model m*x'' + c*x' + k*x = 0 with initial conditions to compute displacement, damping ratio, and settling behavior.
Conversion Tools
Featured
Data Size Converter
Convert data sizes across bytes, KB, MB, GB, and TB.
Useful for storage estimates, file size planning, and cloud budgeting.
Personal
Featured
Debt Payoff Calculator
Estimate months to pay off debt and total interest cost.
Model payoff timelines from balance, APR, and monthly payment assumptions. Great for personal budgeting and debt reduction planning.
Physics
Featured
Density Calculator
Calculate density from mass and volume.
Compute density using the fundamental formula ρ = m/V. Useful for physics, chemistry, and material science applications.
Project Management
Featured
Dependency Risk Heatmap
Quantify dependency risk from blocked items, ownership clarity, and complexity.
Score external/internal dependency risk to identify where delivery bottlenecks are most likely to impact timeline.
Math
Featured
Distance Speed Time Calculator
Solve for distance, speed, or time using the standard motion formula.
Choose whether to solve for distance, speed, or time and provide the remaining values. Useful for travel planning, logistics estimation, and physics homework checks.
Network
Featured
DNS Lookup
Query DNS records by type for a host.
Lookup A, AAAA, CNAME, MX, TXT, and NS records from one page for fast diagnostics.
Network
Featured
DNS Propagation Checker
Check DNS record propagation across major public resolvers.
DNS Propagation Checker queries multiple public resolvers and shows what each one currently returns for a given record type. It helps you verify whether DNS changes are fully visible worldwide or still inconsistent across recursive DNS providers. You can optionally provide an expected value (for example an A record IP or TXT token) to measure match rate directly. This is useful during domain cutovers, mail authentication setup, and outage triage where stale resolver data causes mixed behavior. Results reflect resolver caches and query timing at the moment you run the check.
Network
Featured
DNS Record Builder
Generate valid DNS zone record lines for common record types.
Build A, AAAA, CNAME, MX, TXT, and SRV records quickly with syntax guidance and defaults.
Data
Featured
Donut Chart Generator
Create donut charts from labeled values with configurable center hole.
Paste labeled values and generate a donut chart with percentages, totals, and adjustable hole size.
Marine & Navigation
Featured
Drift Estimator
Estimate set-and-drift impact on course over ground and offset.
Combine vessel heading/speed with current and wind drift vectors to estimate course over ground, speed over ground, and accumulated position offset. Useful for pilotage and small-vessel planning where environmental set can significantly change track over time.
Project Management
Featured
Earned Value Calculator
Calculate CPI, SPI, CV, and EAC for schedule/cost control.
Apply earned value management formulas to detect budget and schedule drift early.
Developer
Featured
EBCDIC Converter
Convert text to EBCDIC hex and vice-versa.
Translate strings between UTF-8 and EBCDIC (IBM037) encoding. Useful for mainframe data analysis and legacy system integration.
Engineering
Featured
Electrical Power Calculator
Solve power, voltage, or current from P = V * I.
Convenient electrical triangle calculator for circuits and load estimates.
Conversion Tools
Featured
Energy Converter
Convert energy units: J, kJ, cal, kcal, Wh, kWh, and BTU.
Convert thermal and electrical energy units for engineering, nutrition, and utility contexts.
Developer
Featured
Environment Variable Manager
Convert between .env formats and validate variables.
Convert environment variables between .env, Docker, Kubernetes, and JSON formats.
Marine & Navigation
Featured
ETA Current/Wind Compensation Calculator
Estimate ETA delay from current and wind speed penalties.
Adjust calm-water ETA by combining current component and wind-related speed penalty. Useful for passage updates and operational timing when environmental conditions reduce effective speed.
Math
Featured
Euler Method ODE Solver
Approximate ODE solutions with the forward Euler method.
Numerically solve dy/dx = a*x + b*y + c from initial conditions, step size, and step count.
Conversion Tools
Featured
EXIF Remover
Remove image metadata by re-encoding locally in-browser.
Strip EXIF and other embedded metadata from JPEG/PNG/WebP files using a local browser conversion flow.
Math
Featured
Exponential Growth Decay Calculator
Model growth or decay over periods with compounding behavior.
Calculate exponential growth/decay trajectories using an initial value, periodic rate, and period count.
Math
Featured
Factorial Permutation Combination Calculator
Compute n!, nPr, and nCr for combinatorics and probability problems.
Enter n and r to calculate factorial, permutations, and combinations in one place. Useful for exam prep, probability work, and algorithmic problem solving.
Industrial
Featured
Fluid Depth, Density, Gravity & Pressure Calculator
Solve for any variable in the hydrostatic equation P = ρgh.
Universal hydrostatic calculator. Enter any 3 values (depth, density, gravity, pressure) to solve for the 4th using P = ρgh.
Physics
Featured
Flywheel Energy Calculator
Calculate kinetic energy stored in a rotating flywheel.
Determine the kinetic energy stored in a flywheel based on its moment of inertia and angular velocity, or derived from its shape, mass, radius, and RPM.
Physics
Featured
Force & Area to Pressure Calculator
Calculate pressure from force and area.
Compute pressure using P = F/A. Useful for mechanical engineering, hydraulics, and physics applications.
Physics
Featured
Frequency Period Converter
Convert between frequency and period.
Bidirectional converter between frequency (Hz) and period (seconds) using f = 1/T. Useful for electronics, signal processing, and wave analysis.
Conversion Tools
Featured
Fuel Economy Converter
Convert fuel economy across mpg US, mpg UK, L/100km, and km/L.
Convert fuel efficiency units used across automotive regions with full equivalents output.
Marine & Navigation
Featured
Fuel Endurance + Reserve Calculator
Calculate endurance and range after applying reserve fuel policy.
Plan voyage endurance from usable fuel, burn rate, reserve percentage, and cruise speed. Useful for coastal and offshore planning where reserve policy must be explicit before departure.
Data
Featured
Funnel Chart Generator
Create funnel charts from stage values and inspect conversion drop-off.
Paste stage-value rows and generate a funnel view with relative widths and stage conversion percentages.
Data Visualization
Featured
Gantt Chart Generator
Create project timeline visualizations.
Generate Gantt charts for project planning with task timelines and dependencies.
Industrial
Featured
Gauge + Barometric to Absolute Pressure Calculator
Convert gauge and barometric pressure to absolute pressure.
Calculate absolute pressure from gauge and barometric readings: P_abs = P_gauge + P_barometric.
Developer
Featured
Git Diff Stat Calculator
Calculate lines added/removed from git diff output.
Analyze git diffs with file-by-file breakdown of additions and deletions.
Education
Featured
GPA Calculator
Compute GPA from course credits and grade points.
Enter credits and grade points per course to calculate weighted GPA. Helpful for semester planning, scholarship targets, and academic progress tracking.
Marine & Navigation
Featured
Great Circle vs Rhumb Line Calculator
Compare great-circle and rhumb-line distance, bearing, and ETA.
Compute both great-circle and rhumb-line route metrics between two coordinates. Useful for offshore route planning and voyage briefing when deciding between shortest-distance routing and constant-bearing simplicity.
Developer Tools
Featured
Hash Generator
Generate MD5, SHA1, and SHA256 hashes from input text.
Instantly create common cryptographic hash outputs for strings and payload snippets. Useful for development workflows, debugging, and quick integrity checks.
Data
Featured
Heatmap Generator
Create heatmaps from row-column-value data matrices.
Paste row/column/value entries and generate a color-intensity matrix for quick pattern detection.
Conversion Tools
Featured
HEIC to JPG Converter
Convert HEIC images to JPG where browser support is available.
Upload HEIC files and export JPG output using local browser decoding when supported by platform capabilities.
Data
Featured
Histogram Generator
Create histograms from numeric samples to view distribution across bins.
Paste numeric values, choose bin count, and generate a histogram with bin ranges, counts, and summary stats.
Industrial
Featured
Horizontal Cylindrical Tank Contents Calculator
Calculate liquid volume in horizontal cylindrical tanks.
Determine liquid volume from depth in horizontal cylindrical tanks using circular segment geometry. Essential for fuel storage and process tanks.
Developer Tools
Featured
HTTP Headers Checker
Fetch response headers for a URL using HEAD requests.
Inspect status code and HTTP response headers to validate caching, security, and delivery setup.
Chemistry
Featured
Ideal Gas Law Calculator
Solve pressure, volume, moles, or temperature with PV=nRT.
Use the ideal gas law to solve one missing variable given the other three. Great for gas-law homework, exam prep, and quick unit-aware checks.
Conversion Tools
Featured
Image Watermark Tool
Add text watermarks to images locally in-browser.
Apply configurable text watermarks with position, color, opacity, and font size controls, then download the result.
Solar & Power
Featured
Inverter Sizing Calculator
Determine recommended inverter continuous and surge ratings.
Size your inverter based on simultaneous continuous loads and peak motor starting surges.
Business
Featured
Invoice Splitter
Split invoices by team member, project, or department with transparent math.
Break a single invoice into clean allocations across people, teams, or clients. This tool is useful for agencies, partnerships, and operations teams who need auditable cost distribution. Add total amount, tax, discounts, and custom allocation percentages. Export a plain-language summary that can be attached to accounting records.
Network
Featured
IP Classifier
Classify IPv4/IPv6 addresses by private, loopback, multicast, and more.
Instantly classify addresses for troubleshooting, security reviews, and docs validation.
Network
Featured
IP Lookup
Inspect IP type and reverse DNS details.
Look up IPv4/IPv6 properties including private/public class, loopback, multicast, and reverse DNS.
Conversion Tools
Featured
JPG to PNG Converter
Convert JPG images to PNG format in-browser.
Upload a JPG image and convert it to PNG for lossless workflows and transparent-ready editing.
Developer
Featured
JSON Diff Viewer
Compare two JSON objects and highlight differences.
Side-by-side JSON comparison with color-coded additions, deletions, and modifications.
Developer Tools
Featured
JWT Decoder
Decode JWT header and payload claims for debugging.
Paste a JWT token to decode Base64URL header and payload, inspect registered claims, and check timestamp fields quickly.
Physics
Featured
Kinetic Energy Calculator
Compute kinetic energy and momentum from mass and velocity.
Calculate energy with KE = 1/2 m v² and momentum p = m v in one page. Useful for mechanics problems and practical motion estimates.
Converters
Featured
Length/Distance Converter
Convert between metric and imperial length units.
Convert lengths and distances between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles.
Math
Featured
Linear Regression Calculator
Fit a best-fit line from point data and compute r and R².
Enter x,y pairs to estimate slope, intercept, and correlation quality.
Data
Featured
Line Chart Generator
Create line charts from labeled values to visualize change over time.
Paste labeled values and generate a line chart with trend direction, min/max range, and point-by-point output.
Industrial
Featured
Liquid Level to Hydrostatic Pressure Calculator
Calculate hydrostatic pressure from liquid level.
Convert liquid level to pressure using P = ρgh. Essential for tank pressure calculations and sensor calibration.
Financial
Featured
Loan Calculator
Calculate monthly payments and total interest for loans.
Compute monthly loan payments, total interest paid, and amortization details based on principal, interest rate, and term.
Design & Branding
Featured
Logo Variation Generator
Generate multiple local SVG logo variations from one brand input.
Create and download wordmark and mark-based logo variations with customizable style and color settings.
Developer
Featured
Markdown Preview
Live markdown editor with real-time preview.
Write and preview markdown with GitHub Flavored Markdown support.
Math
Featured
Matrix 2x2 Analyzer
Analyze determinant, inverse, trace, and eigenvalues for 2x2 matrices.
Useful for linear algebra classes, engineering math, and matrix sanity checks.
Project Management
Featured
Milestone Slip Calculator
Measure schedule slip based on planned vs actual milestone progress.
Estimate slip percentage, projected delay days, and forecasted delivery date from milestone execution pace.
Chemistry
Featured
Molarity Calculator
Solve molarity, moles, or volume using M = n/V.
Calculate solution concentration and dilution prep values from moles and volume. Useful for lab prep, chemistry coursework, and quick concentration checks.
Finance
Featured
Mortgage Calculator
Estimate monthly mortgage payments, total paid, and interest.
Calculate fixed-rate mortgage payments from principal, APR, and term.
Network
Featured
MTU MSS Calculator
Calculate effective payload and TCP MSS from MTU and tunnel overhead.
Model encapsulation overhead across IPv4/IPv6 and common tunnels to prevent fragmentation issues.
Physics
Featured
Newton Second Law Calculator
Solve force, mass, or acceleration using F = m * a.
Use Newton's second law to solve one unknown variable when the other two are known. Helpful for physics classes, engineering checks, and quick unit-based sanity tests.
Statistics
Featured
Normal Probability Calculator
Compute probability between two bounds in a normal distribution.
Converts bounds to z-scores and calculates probability mass between them.
Physics
Featured
Ohms Law Calculator
Solve voltage, current, or resistance and compute electrical power.
Apply Ohm's law (V = I * R) to electrical circuit basics and derive missing values. Includes quick power estimate using P = V * I.
Statistics
Featured
One-Sample t-Test Calculator
Compute one-sample t-statistic from sample values and hypothesized mean.
Enter sample values and compare against a target mean using the one-sample t-test setup.
Physics
Featured
Orbital Mechanics Calculator
Compute circular orbital speed, escape speed, and orbital period.
Estimate orbital dynamics around a central body from mass and altitude with physically grounded equations.
Network
Featured
Packet Loss Impact Estimator
Estimate throughput degradation from loss and RTT assumptions.
Use a practical TCP-oriented rule-of-thumb model to quantify packet loss impact on effective throughput.
Data
Featured
Pareto Chart Generator
Create Pareto charts with sorted categories and cumulative percentages.
Paste category values to generate a Pareto view with descending bars and cumulative contribution.
Developer Tools
Featured
Password Generator
Generate secure random passwords with customizable rules.
Create strong passwords with configurable length and character sets.
Developer Tools
Featured
Password Strength Checker
Evaluate password strength with score, entropy estimate, and improvement tips.
Check password quality using length, character classes, and common-pattern heuristics to quickly identify weak credentials.
Statistics
Featured
Pearson Correlation Calculator
Calculate Pearson r and R² from paired X and Y datasets.
Quantify linear relationship strength between two numeric variables.
Math
Featured
Percentage Change Calculator
Compute absolute and percentage increase/decrease between two values.
Enter initial and final values to calculate both absolute change and percent change instantly. Useful for pricing updates, KPI shifts, trend reports, and quick sanity checks.
Chemistry
Featured
pH Calculator
Convert hydrogen ion concentration to pH and classify acidity/basicity.
Compute pH and pOH from [H+] or derive [H+] from pH quickly. Useful for acid-base questions, buffer prep, and classroom exercises.
Data
Featured
Pie Chart Generator
Create pie charts from labeled values and visualize proportional shares.
Paste labeled values and generate a pie chart with percentages, totals, and a clean legend for quick reporting.
Conversion Tools
Featured
PNG to JPG Converter
Convert PNG images to JPG format in-browser.
Upload a PNG file and export JPG output with adjustable quality settings.
Statistics
Featured
Poisson Probability Calculator
Calculate exact and cumulative Poisson event probabilities.
Estimate event-count probabilities over fixed intervals when events are rare and independent.
Math
Featured
Polynomial Derivative Evaluator
Evaluate cubic polynomial derivatives and curvature at a chosen x value.
Compute f(x), f'(x), and f''(x) for ax^3+bx^2+cx+d with instant output.
Network
Featured
Port Range Planner
Plan port ranges against concurrent session requirements.
Estimate whether a configured port interval can handle projected concurrency safely.
Conversion Tools
Featured
Power Density Converter
Convert power density between hp/L and kW/L.
Convert engine and motor specific output metrics across horsepower per liter and kilowatt per liter.
Conversion Tools
Featured
Power Unit Converter
Convert between PS, HP, BHP, and kW power units.
Convert engine and motor power ratings across PS, HP, BHP, and kW with quick all-unit output.
Conversion Tools
Featured
Pressure Altitude Converter
Calculate pressure altitude from altimeter settings or station pressure.
Convert aviation/weather pressure inputs to pressure altitude in feet and meters.
Industrial
Featured
Pressure to Liquid Level Calculator
Calculate liquid level from pressure measurement.
Convert pressure readings to liquid level height using hydrostatic formula h = P/(ρg). Useful for tank level monitoring and process control.
Business
Featured
Pricing Tier Designer
Model tier pricing and customer mix to forecast monthly and annual revenue.
Build a quick revenue model across Starter, Growth, and Scale tiers with customer counts and plan prices. This helps product and GTM teams pressure-test pricing strategy before experiments or launches.
Business
Featured
Profit Margin Calculator
Compute profit, margin, and markup from revenue and cost.
Quick check for profitability, pricing discussions, and target planning.
Solar & Power
Featured
PV Stringing Helper
Analyze series and parallel solar panel configurations.
Optimize panel stringing based on Voc, Vmp, temperature coefficients, and MPPT voltage limits.
Conversion Tools
Featured
QR Code Generator
Generate customizable QR codes from text or URLs.
Create SVG QR codes for links, text, or credentials. Tweak size and colors to match your branding.
Math
Featured
Quadratic Equation Solver
Solve ax² + bx + c = 0 with real or complex roots.
Quickly compute discriminant and roots for quadratic equations with clear output formatting. Suitable for students, tutors, and engineering pre-checks.
Data
Featured
Radar Chart Generator
Create radar charts from metric-value pairs across a shared scale.
Paste metric values and generate a radar/spider chart to compare multi-dimensional profiles.
Math
Featured
Random Number Generator
Generate random numbers with range, count, and uniqueness options.
Create integer or decimal random samples with configurable bounds and uniqueness constraints.
Developer Tools
Featured
Random String Generator
Generate random strings with configurable length and character sets.
Create random tokens for IDs, test data, and temporary secrets with optional uppercase, digits, and symbols.
Physics
Featured
RC Circuit Transient Calculator
Analyze capacitor voltage/current over time for RC charge and discharge.
Compute RC time constant, transient voltage/current response, and milestone times (63%, 90%, 99%).
Industrial
Featured
Rectangular Tank Contents Calculator
Calculate liquid volume in rectangular tanks.
Determine liquid volume in rectangular tanks from dimensions using V = l × w × h. Ideal for aquariums, pools, and industrial vessels.
Developer Tools
Featured
Regex Tester
Test regular expressions with flags, matches, and capture groups.
Run regex patterns against text input and inspect match positions and captures quickly.
Statistics
Featured
Relative Risk Odds Ratio Calculator
Compute RR, OR, and confidence intervals from a 2x2 contingency table.
Analyze exposure-outcome association with relative risk, odds ratio, and 95% confidence bounds.
Project Management
Featured
Resource Allocation Planner
Balance workload against team capacity using time and utilization assumptions.
Plan team allocation by comparing total work hours against available capacity and required team size.
Project Management
Featured
Risk Matrix Scorer
Score project risks using probability, impact, and expected loss.
Apply a standard 5x5 risk matrix with expected financial exposure to prioritize mitigation efforts.
Business
Featured
ROI Calculator
Calculate Return on Investment and annualized returns.
Compute ROI percentage, net profit, and annualized returns for investment analysis.
Engineering
Featured
Safety Factor Calculator
Calculate safety factor from material strength and working stress.
Estimate design safety margin by comparing allowable strength against expected load stress. Useful for preliminary design checks and engineering documentation.
Statistics
Featured
Sample Size Calculator
Estimate required sample size from confidence level, margin error, and proportion.
Supports infinite-population and finite-population adjusted sample size estimates.
Data Visualization
Featured
Sankey Diagram Generator
Visualize flow data with Sankey diagrams.
Create Sankey diagrams to visualize flows, transfers, and process relationships.
Personal
Featured
Savings Goal Calculator
Find required monthly savings contribution to reach a target goal.
Plan a target amount with current savings, time horizon, and expected return.
Data
Featured
Scatter Plot Generator
Create scatter plots from x,y points to inspect relationships.
Paste x,y points and generate a scatter plot with axis ranges and correlation estimate for quick analysis.
Project Management
Featured
Scope Creep Detector
Detect scope growth risk and delivery pressure before deadlines are missed.
Compare initial and current scope, then estimate the throughput increase needed to still finish on plan.
Developer Tools
Featured
SHA256 Generator
Generate SHA256 hashes from plain text input.
Create deterministic SHA256 digests for checksums, signatures, and debugging workflows.
Conversion Tools
Featured
Shoe Size Converter
Convert shoe sizes across US men's, US women's, UK, EU, and JP(cm).
Approximate shoe size conversion across major regional sizing systems.
Design & Branding
Featured
Social Image Generator
Create social preview images from text, colors, and platform size presets.
Generate downloadable SVG social cards for Open Graph, Twitter/X, LinkedIn, and Instagram using local rendering only.
Solar & Power
Featured
Solar Array Size Calculator
Calculate required PV array size and panel count.
Determine the required DC solar capacity based on daily energy usage, peak sun hours, and system efficiency.
Solar & Power
Featured
Solar Charge Time Estimator
Estimate hours to reach target battery state of charge.
Predict the time required to recharge batteries based on present SOC, target SOC, and available charge power.
Model Rocketry
Featured
Specific Impulse (Isp) Calculator
Calculate Specific Impulse (Isp) for rocket engines.
Specific impulse (Isp) is a measure of how efficiently a rocket engine uses its propellant. Calculate it using thrust and mass flow rate, or total impulse and propellant mass.
Math
Featured
Sphere Volume Calculator
Calculate sphere volume and surface area from radius.
Compute volume, surface area, and diameter from sphere radius using standard geometric formulas.
Project Management
Featured
Sprint Capacity Calculator
Estimate sprint hours and suggested story points from team constraints.
Compute gross, net, and effective sprint capacity after ceremonies, then estimate practical story point target.
Developer
Featured
SQL Formatter
Beautify and format SQL queries.
Format SQL queries with proper indentation and keyword highlighting for better readability.
Developer Tools
Featured
SQL Prettifier
Format SQL queries into readable or compact output.
Paste SQL and convert between pretty-printed and compact forms for debugging, reviews, and docs.
Data
Featured
Stacked Bar Chart Generator
Create stacked bar charts from grouped segment values.
Paste group, segment, value rows and generate stacked bars with legend and group totals.
Math
Featured
Standard Deviation Calculator
Calculate mean, variance, and standard deviation for a dataset.
Paste numeric values to compute population and sample statistics quickly. Useful for analytics, classroom assignments, and data quality checks.
Text Tools
Featured
String Reverser
Reverse text, words, or check for palindromes.
Reverse entire text, reverse word order, and check if text is a palindrome.
Network
Featured
Subnet Calculator
Calculate network, broadcast, host range, and mask details from CIDR.
Analyze IPv4 subnets quickly for network planning, lab setup, and infrastructure troubleshooting.
Network
Featured
Supernet Calculator
Find the smallest covering CIDR for an IPv4 start/end range.
Compute the minimal supernet that covers an address interval for route and ACL simplification.
Conversion Tools
Featured
SVG to PNG Converter
Rasterize SVG files to PNG at configurable scale.
Upload an SVG and export PNG output with selectable scaling for web assets and previews.
Math
Featured
Symbolic Equation Solver
Solve linear and quadratic equations in x with symbolic steps.
Solve equations in one variable (`x`) on a single page and get both simplified form and final roots. This tool accepts equations such as `3x + 9 = 0` and `2x^2 - 5x - 3 = 0`, then normalizes terms to standard form, applies the correct method, and displays symbolic steps you can follow or reuse in notes. It is intended for algebra practice, quick verification before coding formulas, and engineering sanity checks. Current scope is polynomial equations up to degree 2 with real coefficients.
Math
Featured
Symbolic Integral Calculator
Integrate polynomial expressions symbolically and evaluate definite bounds.
Find antiderivatives for polynomial terms (e.g. 3x^2 - 4x + 7) and optionally compute definite integral values.
Conversion Tools
Featured
Temperature Converter
Convert Celsius, Fahrenheit, and Kelvin values instantly.
One-page converter for common scientific and everyday temperature units.
Text Tools
Featured
Text Diff Tool
Compare two texts and highlight differences.
Line-by-line text comparison with color-coded additions, deletions, and statistics.
Network
Featured
Throughput Unit Converter
Convert bps/Kbps/Mbps/Gbps and estimate transfer time.
Translate bandwidth units and estimate file transfer durations for operations and capacity planning.
Marine & Navigation
Featured
Tide Window Planner
Estimate passable tidal windows around high tide for draft-limited transits.
Model a practical tide window from high/low tide heights, charted depth, vessel draft, and safety margin. Useful for bar crossings, marina entries, and shallow-channel planning where timing around high tide matters. The tool estimates available transit duration around high water using a semidiurnal approximation.
Productivity
Featured
Timezone Converter
Convert date and time across common time zones.
Translate timestamps between selected time zones for scheduling and distributed team coordination.
Engineering
Featured
Torque Calculator
Calculate torque from force, lever arm, and angle.
Uses tau = F * r * sin(theta) for quick mechanical calculations.
Conversion Tools
Featured
Torque Converter
Convert torque between Nm, lb-ft, and kgf-m.
Convert mechanical torque units for automotive, motorsport, and engineering workflows.
Data Visualization
Featured
Tree Map Generator
Visualize hierarchical data with tree maps.
Create tree maps for hierarchical data visualization with size and color encoding.
Math
Featured
Triangle Analyzer
Analyze triangle validity, perimeter, area, angles, and type.
Enter side lengths to classify triangles and compute key geometry outputs for coursework and design.
Marine & Navigation
Featured
Turning Circle / Advance / Transfer Estimator
Estimate turning radius, tactical diameter, advance, and transfer.
Generate first-pass turning characteristics from speed, rudder angle, and vessel length. Useful for maneuvering briefings and pilot exchange preparation when full sea-trial data is unavailable.
Marine & Navigation
Featured
Under Keel Clearance Calculator
Assess UKC using depth, tide, squat, wave allowance, and safety margin.
Estimate under keel clearance for channels and port approaches by combining charted depth, tide height, vessel draft, squat, and operational margins. Useful for go/no-go checks during shallow-water transits.
Developer Tools
Featured
Unix Timestamp Converter
Convert unix timestamps to UTC datetime and back.
Translate epoch seconds and parseable datetime strings for logs, APIs, and debugging workflows.
Network
Featured
Uptime SLA Calculator
Translate SLA percentage targets into allowed downtime windows.
Compute maximum allowable downtime for day, week, month, or year across common uptime targets.
Developer Tools
Featured
URL Encoder Decoder
Encode and decode URL strings for safe query and path handling.
Convert text to URL-encoded form and decode encoded strings for debugging links, query params, and integrations.
Math
Featured
Vector Operations Calculator
Run dot product, angle, magnitude, sum, difference, and cross product.
Compute core 2D/3D vector operations for mechanics, graphics, and linear algebra tasks.
Project Management
Featured
Velocity Stability Index
Analyze sprint velocity consistency with a normalized stability index.
Convert historical sprint velocities into variance, coefficient of variation, and a stability score for release planning confidence.
Industrial
Featured
Vertical Cylindrical Tank Contents Calculator
Calculate liquid volume in vertical cylindrical tanks.
Compute liquid volume from height in vertical cylindrical tanks using V = πr²h. Perfect for water tanks and storage vessels.
Network
Featured
VLSM Planner
Plan variable-length subnet allocations from a base CIDR.
Allocate host requirements into efficiently sized subnets and verify whether all requests fit in the parent block.
Engineering
Featured
Voltage Divider Calculator
Compute output voltage for two-resistor divider circuits.
Useful for quick analog design checks and electronics prototyping.
Data
Featured
Waterfall Chart Generator
Create waterfall charts from positive and negative step changes.
Paste labeled deltas and generate a waterfall view showing cumulative movement from start to finish.
Converters
Featured
Weight/Mass Converter
Convert between metric and imperial weight units.
Convert weights and masses between milligrams, grams, kilograms, tonnes, ounces, pounds, and tons.
Network
Featured
What's My IP
Show the client IP address seen by the server.
Display the current request IP along with forwarded header hints for quick troubleshooting.
Text Tools
Featured
Word Counter
Count words, characters, sentences, and estimate reading time.
Comprehensive text statistics including word count, character count (with/without spaces), sentences, paragraphs, and reading time estimation.
Developer Tools
Featured
XML Formatter
Pretty-print, compact, and validate XML quickly.
Format XML into readable indented output or compact form, and catch parse errors for faster debugging.
Lifestyle
Featured
Zodiac Birth Chart Calculator
Estimate Sun, Moon, Rising, and Midheaven signs from birth data.
Generate a quick tropical astrology summary from birth date, local time, and place. The tool estimates Sun sign, Moon sign, Ascendant (rising sign), and Midheaven using astronomical approximations. It supports city presets and manual latitude/longitude overrides for better rising-sign accuracy. Use it for quick orientation, profile enrichment, or content personalization workflows where you need practical outputs on one page. This is not a full professional natal chart engine; results are approximate and intended for educational or lifestyle use.
Personal
Age Calculator
Calculate age in years, days, and weeks from birth date.
Simple date-based age computation for personal and admin use.
Developer Tools
AI Prompt Optimizer
Analyze and improve AI prompts for clarity and effectiveness.
Evaluate your AI prompts across clarity, specificity, and structure dimensions. Get real-time scores, identify vague language, and receive suggestions for improvement. This tool helps craft prompts that yield better, more consistent results from language models without requiring external APIs. Enter any prompt and receive instant analysis with actionable improvement suggestions. Works for ChatGPT, Claude, Gemini, and any LLM. Use this before sending important prompts to catch clarity issues and optimize for response quality.
Math
Arithmetic Sequence Solver
Find nth term and sum of an arithmetic progression from a, d, and n.
Solve arithmetic progression problems with first term, common difference, and number of terms. Great for school math, exam preparation, and quick sequence verification.
Developer Tools
Base64 Encoder Decoder
Encode and decode Base64 text directly in browser.
Quick utility for API payload prep, debugging, and data transport checks.
Engineering
Beam Deflection Calculator
Estimate max deflection for a simply-supported beam with center load.
Uses classic formula delta = PL^3/(48EI) for quick structural checks.
Math
Binomial Probability Calculator
Compute exact and cumulative binomial probabilities for n, k, p.
Great for probability exercises, risk estimation, and stats exam prep.
Statistics
Chi-Square GOF Calculator
Calculate chi-square goodness-of-fit statistic from observed vs expected counts.
Useful for categorical fit checks and introductory hypothesis testing workflows.
Math
Circle Calculator
Calculate diameter, circumference, and area from a circle radius.
Input radius and get all key circle measurements with precise decimal outputs. Suitable for geometry practice, engineering checks, and classroom demos.
Legal Ops
Contract Clause Summarizer
Turn dense legal language into plain summaries with key risk highlights.
Paste clause text and get a concise summary, suggested action points, and common risk pattern flags. Useful for founders, procurement, and operations teams who need fast first-pass contract understanding.
Project Management
Critical Path Estimator
Estimate critical path duration and potential schedule compression gains.
Model key project phase durations and approximate impact of test parallelization. Useful for project kickoff planning and timeline communication.
Data
CSV Cleaner
Clean rows, normalize columns, and remove duplicates quickly.
Upload or paste CSV content to detect duplicate rows, empty records, and inconsistent formatting. Normalize headers, trim whitespace, and export a cleaned file in one flow. Useful for marketing, operations, and analytics teams before importing data into other systems.
Productivity
Date Difference Calculator
Calculate days and weeks between two dates.
Useful for planning timelines, deadlines, and scheduling windows.
Chemistry
Dilution Calculator
Use C1V1=C2V2 to solve dilution and solution prep problems.
Determine unknown concentration or volume for dilution planning with one equation. Great for lab workflows, stock solution prep, and chemistry practice.
Business
Discount Calculator
Compute discount amount, post-discount price, and final total with tax.
Useful for retail pricing, promotions, and quick checkout math.
Physics
Doppler Shift Calculator
Calculate observed frequency shift from source/observer relative motion.
Evaluate Doppler frequency shift for wave systems using source and observer speeds with directional motion.
Productivity
Fake Address Generator
Generate synthetic US-style addresses for non-production use.
Produce random formatted addresses for QA forms, demos, and test datasets.
Math
Fibonacci Sequence Generator
Generate Fibonacci numbers and inspect nth term and sequence sum.
Choose how many terms to generate and instantly get the sequence, nth value, and total sum. Great for math practice, coding interviews, and algorithm demonstrations.
Math
Fraction Simplifier
Reduce fractions to simplest form and convert to decimal instantly.
Enter numerator and denominator to simplify fractions using GCD and view decimal form. Helpful for math homework, tutoring sessions, and quick arithmetic checks.
Statistics
F Test Variance Calculator
Compare sample variances with F statistic and degrees of freedom.
Compute two-sample variance comparison metrics to support homogeneity checks.
Math
GCD LCM Calculator
Find greatest common divisor and least common multiple for two integers.
Input two integers to calculate GCD, LCM, and whether they are coprime. Great for number theory basics, classroom exercises, and programming prep.
Statistics
Geometric Mean Calculator
Find geometric mean for positive-number datasets.
Useful for growth rates, index performance, and multiplicative process summaries.
Statistics
Harmonic Mean Calculator
Calculate harmonic mean for rates and ratios.
Best for averaging speeds, price multiples, and other ratio-based metrics.
Network
IPv4 to Integer Converter
Convert IPv4 addresses to 32-bit integers and back.
Useful for database indexing, scripting, firewall rule systems, and low-level networking work.
Network
IPv6 Compressor Expander
Compress or fully expand IPv6 notation.
Normalize IPv6 addresses for documentation, automation pipelines, and compliance checks.
Network
Latency Budget Calculator
Allocate and track end-to-end latency budget across system components.
Break down response-time targets into frontend, backend, DB, network, and external dependency budgets.
Physics
Lens Imaging Calculator
Solve thin-lens image distance, magnification, and orientation.
Use the thin lens equation to determine real/virtual image characteristics and image size scaling.
Math
Logarithm Calculator
Compute logarithms for custom base and value inputs.
Solve log_b(x) quickly and verify with exponent reconstruction.
Writing & Content
Lorem Ipsum Generator
Generate placeholder text by words, sentences, or paragraphs.
Quickly create lorem ipsum filler text for layouts, prototypes, and content staging.
Productivity
Meeting Action Extractor
Turn messy notes into clear owners, deadlines, and next actions.
Paste meeting notes or transcripts and generate action items grouped by owner and due date. This saves teams from manual follow-up and missed commitments. Designed for project managers and founders who need immediate post-meeting clarity.
Project Management
Meeting Cost Calculator
Estimate meeting cost per session, week, month, and year.
Translate meeting load into direct labor cost to improve planning discipline and reduce unnecessary meetings.
Statistics
Moving Average Calculator
Compute rolling averages over a configurable window.
Useful for smoothing noisy series and spotting trend direction.
Statistics
Percentile Rank Calculator
Find percentile rank of a target value within a dataset.
Helpful for score interpretation, benchmarking, and education metrics.
Conversion Tools
Pressure Converter
Convert pressure units: Pa, kPa, bar, psi, and atm.
Ideal for engineering checks, tire pressure, and process control tasks.
Math
Prime Number Checker
Check whether a number is prime and view factors when it is not.
Enter an integer to test primality and classify the number quickly. Helpful for schoolwork, coding practice, and cryptography fundamentals.
Physics
Projectile Motion Calculator
Estimate flight time, max height, and range from launch speed and angle.
Solve projectile motion assuming no air resistance and equal launch/landing heights. Great for introductory mechanics practice and trajectory intuition.
HR & Hiring
PTO Accrual Calculator
Calculate accrued and remaining paid time off based on annual allowance.
Estimate earned PTO from annual policy, months worked, and used days. Helpful for HR operations and employee leave planning.
Productivity
Random Name Generator
Generate random full names for brainstorming or test data.
Create batches of realistic placeholder names with optional middle initials for demos and mockups.
Chemistry
Reaction Yield Calculator
Calculate percent yield and loss from theoretical and actual yield values.
Enter theoretical and actual yield to evaluate reaction efficiency. Helpful for lab reports, stoichiometry checks, and process optimization basics.
Writing & Content
Readability Score Checker
Analyze text readability with Flesch score and writing complexity band.
Paste text to evaluate readability and estimate how easy it is to understand. Useful for blog posts, product docs, and marketing copy refinement.
Engineering
Reynolds Number Calculator
Estimate fluid flow regime using Reynolds number.
Classifies laminar, transitional, and turbulent flow from fluid properties.
Conversion Tools
Speed Converter
Convert speed across m/s, km/h, mph, and knots.
Useful for transport planning, sports metrics, and navigation.
Developer Tools
SSL Certificate Validator
Check SSL/TLS certificate validity and details.
Paste an SSL certificate or enter a domain to validate certificate chain, expiration date, key strength, and issuer details. Identifies warnings like upcoming expiration or weak cryptography. Supports PEM-formatted certificates and automatic domain lookups. Essential for DevOps teams managing certificate lifecycles and security compliance. Use this before deploying to catch certificate issues early and ensure uninterrupted HTTPS availability.
Engineering
Thermal Expansion Calculator
Calculate linear expansion from alpha, temperature change, and length.
Useful for materials, piping, and tolerance planning under temperature shifts.
Productivity
Timezone Overlap Planner
Find working-hour overlaps across distributed teams.
Pick multiple locations and availability windows to instantly see overlap slots that work for everyone. Built for remote teams coordinating calls across regions without guesswork.
Personal
Tip Calculator
Calculate tip amount, total bill, and per-person split.
Quickly split restaurant bills with configurable tip percentage and party size.
Conversion Tools
Unit Converter
Convert length values across metric and imperial units.
Convert between meters, kilometers, centimeters, millimeters, miles, feet, and inches. Useful for engineering specs, logistics, and daily conversion tasks.
Developer Tools
User Agent Parser
Parse browser, OS, and device from user-agent strings.
Analyze a user-agent string and detect browser family, operating system, and device class.
Marketing
UTM Link Builder
Generate campaign links with consistent UTM naming standards.
Build clean, trackable campaign URLs with source, medium, campaign, and optional term/content fields. Enforce naming conventions to improve analytics quality. Ideal for growth marketers running multi-channel campaigns who need fast and consistent tagging.
Operations
Vendor Scorecard
Rank vendors using weighted criteria for faster, defensible procurement choices.
Compare up to three vendors using weighted scoring across price, reliability, and support metrics. This produces a transparent ranking framework for procurement and operations decisions.
Conversion Tools
Volume Converter
Convert liters, milliliters, gallons, quarts, and cups.
Helps with recipes, lab prep, and fluid volume planning.
Physics
Wave Speed Calculator
Solve wave speed, frequency, or wavelength using v = f * lambda.
Choose which variable to solve and compute wave relationships for sound, light, or general wave problems. Includes period output from frequency.
Conversion Tools
Weight Converter
Convert kg, g, lb, oz, and tonnes accurately.
Useful for shipping, nutrition, fitness, and engineering workflows.
Math
Weighted Average Calculator
Compute weighted average from value and weight lists.
Ideal for grading, portfolio weighting, KPI scoring, and multi-factor decision models.
Network
WHOIS Lookup
Fetch WHOIS registration data for domains.
Retrieve raw WHOIS output for domain ownership and registrar metadata checks.
Network
Wildcard Mask Calculator
Convert subnet masks into wildcard masks for ACL rules.
Generate wildcard masks and binary mask views for router and firewall ACL configuration.
Math
Z-Score Percentile Calculator
Convert values to z-scores and estimate normal-distribution percentile.
Useful for test scores, benchmarking, and statistical interpretation.