ToolPatch

One page. One job. Done.

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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    Conversion Tools
    Featured

    Torque Converter

    Convert torque between Nm, lb-ft, and kgf-m.

    Convert mechanical torque units for automotive, motorsport, and engineering workflows.

    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

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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

    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.