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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Engineering
Featured
Electrical Power Calculator
Solve power, voltage, or current from P = V * I.
Convenient electrical triangle calculator for circuits and load estimates.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Developer Tools
Featured
Password Generator
Generate secure random passwords with customizable rules.
Create strong passwords with configurable length and character sets.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Engineering
Featured
Torque Calculator
Calculate torque from force, lever arm, and angle.
Uses tau = F * r * sin(theta) for quick mechanical calculations.
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.
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.
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.
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.
Personal
Age Calculator
Calculate age in years, days, and weeks from birth date.
Simple date-based age computation for personal and admin use.
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.
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.
Math
Logarithm Calculator
Compute logarithms for custom base and value inputs.
Solve log_b(x) quickly and verify with exponent reconstruction.
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.
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.
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.
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.
Math
Z-Score Percentile Calculator
Convert values to z-scores and estimate normal-distribution percentile.
Useful for test scores, benchmarking, and statistical interpretation.