Everyday tools
Unit converter
Convert length, mass and temperature using explicit units.
Color contrast checker
Calculate the contrast ratio between two colors and compare WCAG AA and AAA text thresholds.
Date difference calculator
Calculate the number of calendar days between two dates.
Age calculator
Calculate calendar age in years, months and days on a selected date.
Percentage calculator
Calculate a percentage of a value.
Discount calculator
Calculate discount amount and final price.
VAT / sales tax calculator
Calculate net, tax and gross amounts for exclusive or inclusive tax.
Tip & split calculator
Calculate tip, total bill and equal per-person amount.
Margin & markup calculator
Calculate profit, margin and markup from cost and selling price.
Loan payment calculator
Calculate a fixed-rate amortizing monthly payment and total interest.
Interest calculator
Calculate simple or periodically compounded interest.
Aspect ratio calculator
Calculate numeric and simplified width-to-height ratio.
Megapixel calculator
Calculate total pixels and decimal megapixels from image dimensions.
File transfer time calculator
Estimate ideal transfer time from file size and link speed.
Screen PPI calculator
Calculate display pixel density from resolution and physical diagonal size.
DPI / print size calculator
Calculate physical print size from pixel dimensions and DPI.
Resize dimension calculator
Calculate proportional resized dimensions from one target dimension.
Video bitrate calculator
Estimate available video bitrate from target size, duration and audio bitrate.
Media file size calculator
Estimate encoded audio or video size from constant bitrate and duration.
Unix permission calculator
Convert three-digit octal permissions and nine-character rwx notation.
Time zone converter
Convert a known absolute instant to a target IANA time zone using the browser runtime’s DST-aware time-zone data.
Standard Calculator
Use Standard Calculator locally in your browser with bounded inputs and deterministic formulas.
Scientific Calculator
Use Scientific Calculator locally in your browser with bounded inputs and deterministic formulas.
Fraction Calculator
Use Fraction Calculator locally in your browser with bounded inputs and deterministic formulas.
Ratio Calculator
Use Ratio Calculator locally in your browser with bounded inputs and deterministic formulas.
Proportion Calculator
Use Proportion Calculator locally in your browser with bounded inputs and deterministic formulas.
Factor Calculator
Use Factor Calculator locally in your browser with bounded inputs and deterministic formulas.
LCM Calculator
Use LCM Calculator locally in your browser with bounded inputs and deterministic formulas.
GCF / GCD Calculator
Use GCF / GCD Calculator locally in your browser with bounded inputs and deterministic formulas.
Prime Number Checker
Use Prime Number Checker locally in your browser with bounded inputs and deterministic formulas.
Slope Calculator
Use Slope Calculator locally in your browser with bounded inputs and deterministic formulas.
Area Calculator
Use Area Calculator locally in your browser with bounded inputs and deterministic formulas.
Volume Calculator
Use Volume Calculator locally in your browser with bounded inputs and deterministic formulas.
Average Calculator
Use Average Calculator locally in your browser with bounded inputs and deterministic formulas.
Random Number Generator
Use Random Number Generator locally in your browser with bounded inputs and deterministic formulas.
Coin Flip
Use Coin Flip locally in your browser with bounded inputs and deterministic formulas.
Retirement Calculator
Use Retirement Calculator locally in your browser with bounded inputs and deterministic formulas.
Investment Calculator
Use Investment Calculator locally in your browser with bounded inputs and deterministic formulas.
Auto Loan Calculator
Use Auto Loan Calculator locally in your browser with bounded inputs and deterministic formulas.
Mortgage Affordability Calculator
Use Mortgage Affordability Calculator locally in your browser with bounded inputs and deterministic formulas.
Personal Loan Calculator
Use Personal Loan Calculator locally in your browser with bounded inputs and deterministic formulas.
Salary Calculator
Use Salary Calculator locally in your browser with bounded inputs and deterministic formulas.
GPA Calculator
Use GPA Calculator locally in your browser with bounded inputs and deterministic formulas.
Time Calculator
Use Time Calculator locally in your browser with bounded inputs and deterministic formulas.
Hours Calculator
Use Hours Calculator locally in your browser with bounded inputs and deterministic formulas.
Time Card Calculator
Use Time Card Calculator locally in your browser with bounded inputs and deterministic formulas.
BMI Calculator
Use BMI Calculator locally in your browser with bounded inputs and deterministic formulas.
Calorie Calculator
Use Calorie Calculator locally in your browser with bounded inputs and deterministic formulas.
Pregnancy Due Date Calculator
Use Pregnancy Due Date Calculator locally in your browser with bounded inputs and deterministic formulas.
Ovulation Calculator
Use Ovulation Calculator locally in your browser with bounded inputs and deterministic formulas.
Triangle Calculator
Use Triangle Calculator locally in your browser with bounded inputs and deterministic formulas.
Quadratic Formula Calculator
Use Quadratic Formula Calculator locally in your browser with bounded inputs and deterministic formulas.
Nth Root Calculator
Use Nth Root Calculator locally in your browser with bounded inputs and deterministic formulas.
Standard Deviation & Variance Calculator
Use Standard Deviation & Variance Calculator locally in your browser with bounded inputs and deterministic formulas.
Probability Calculator
Use Probability Calculator locally in your browser with bounded inputs and deterministic formulas.
Permutation & Combination Calculator
Use Permutation & Combination Calculator locally in your browser with bounded inputs and deterministic formulas.
Z-Score Calculator
Use Z-Score Calculator locally in your browser with bounded inputs and transparent formulas.
Grade Calculator
Use Grade Calculator locally in your browser with bounded inputs and transparent formulas.
Final Grade Needed Calculator
Use Final Grade Needed Calculator locally in your browser with bounded inputs and transparent formulas.
Mortgage Refinance Break-Even Calculator
Use Mortgage Refinance Break-Even Calculator locally in your browser with bounded inputs and transparent formulas.
Rent vs Buy Calculator
Use Rent vs Buy Calculator locally in your browser with bounded inputs and transparent formulas.
Debt Payoff Calculator
Use Debt Payoff Calculator locally in your browser with bounded inputs and transparent formulas.
Credit Card Payoff Calculator
Use Credit Card Payoff Calculator locally in your browser with bounded inputs and transparent formulas.
Debt-to-Income Ratio Calculator
Use Debt-to-Income Ratio Calculator locally in your browser with bounded inputs and transparent formulas.
Savings Goal Calculator
Use Savings Goal Calculator locally in your browser with bounded inputs and transparent formulas.
Future Value Calculator
Use Future Value Calculator locally in your browser with bounded inputs and transparent formulas.
Present Value Calculator
Use Present Value Calculator locally in your browser with bounded inputs and transparent formulas.
APY Calculator
Use APY Calculator locally in your browser with bounded inputs and transparent formulas.
APR Calculator
Use APR Calculator locally in your browser with bounded inputs and transparent formulas.
CAGR Calculator
Use CAGR Calculator locally in your browser with bounded inputs and transparent formulas.
ROI Calculator
Use ROI Calculator locally in your browser with bounded inputs and transparent formulas.
NPV Calculator
Use NPV Calculator locally in your browser with bounded inputs and transparent formulas.
IRR Calculator
Use IRR Calculator locally in your browser with bounded inputs and transparent formulas.
Break-Even Calculator
Use Break-Even Calculator locally in your browser with bounded inputs and transparent formulas.
ROAS Calculator
Use ROAS Calculator locally in your browser with bounded inputs and transparent formulas.
Customer Acquisition Cost (CAC) Calculator
Use Customer Acquisition Cost (CAC) Calculator locally in your browser with bounded inputs and transparent formulas.
Customer Lifetime Value (LTV) Calculator
Use Customer Lifetime Value (LTV) Calculator locally in your browser with bounded inputs and transparent formulas.
Burn Rate & Runway Calculator
Use Burn Rate & Runway Calculator locally in your browser with bounded inputs and transparent formulas.
Sales Commission Calculator
Use Sales Commission Calculator locally in your browser with bounded inputs and transparent formulas.
Business Days Calculator
Use Business Days Calculator locally in your browser with bounded inputs and transparent formulas.
Date Add/Subtract Calculator
Use Date Add/Subtract Calculator locally in your browser with bounded inputs and transparent formulas.
Overtime Hours Calculator
Use Overtime Hours Calculator locally in your browser with bounded inputs and transparent formulas.
Running Pace Calculator
Use Running Pace Calculator locally in your browser with bounded inputs and transparent formulas.
1RM Calculator
Use 1RM Calculator locally in your browser with bounded inputs and transparent formulas.
Body Fat Calculator
Use Body Fat Calculator locally in your browser with bounded inputs and transparent formulas.
Concrete Calculator
Use Concrete Calculator locally in your browser with bounded inputs and transparent formulas.
Paint Calculator
Use Paint Calculator locally in your browser with bounded inputs and transparent formulas.
Tile Calculator
Use Tile Calculator locally in your browser with bounded inputs and transparent formulas.
Flooring Calculator
Use Flooring Calculator locally in your browser with bounded inputs and transparent formulas.
Drywall Calculator
Use Drywall Calculator locally in your browser with bounded inputs and transparent formulas.
Roofing Material Calculator
Use Roofing Material Calculator locally in your browser with bounded inputs and transparent formulas.
Brick / Block Calculator
Use Brick / Block Calculator locally in your browser with bounded inputs and transparent formulas.
Board Foot Calculator
Use Board Foot Calculator locally in your browser with bounded inputs and transparent formulas.
Lumber Quantity Calculator
Use Lumber Quantity Calculator locally in your browser with bounded inputs and transparent formulas.
Fence Material Calculator
Use Fence Material Calculator locally in your browser with bounded inputs and transparent formulas.
Stair Calculator
Use Stair Calculator locally in your browser with bounded inputs and transparent formulas.
Ohm's Law Calculator
Use Ohm's Law Calculator locally in your browser with bounded inputs and transparent formulas.
Voltage Drop Calculator
Use Voltage Drop Calculator locally in your browser with bounded inputs and transparent formulas.
Resistor Color Code Calculator
Use Resistor Color Code Calculator locally in your browser with bounded inputs and transparent formulas.
LED Resistor Calculator
Use LED Resistor Calculator locally in your browser with bounded inputs and transparent formulas.
Electricity Cost Calculator
Use Electricity Cost Calculator locally in your browser with bounded inputs and transparent formulas.
Solar Panel Estimate Calculator
Use Solar Panel Estimate Calculator locally in your browser with bounded inputs and transparent formulas.
Battery Runtime Calculator
Use Battery Runtime Calculator locally in your browser with bounded inputs and transparent formulas.
EV Charging Time Calculator
Use EV Charging Time Calculator locally in your browser with bounded inputs and transparent formulas.
Tire Size Comparison Calculator
Use Tire Size Comparison Calculator locally in your browser with bounded inputs and transparent formulas.
Fuel Economy Calculator
Use Fuel Economy Calculator locally in your browser with bounded inputs and transparent formulas.
Fuel Trip Cost Calculator
Use Fuel Trip Cost Calculator locally in your browser with bounded inputs and transparent formulas.
Shipping Package Calculator
Shipping Package Calculator. Run the workflow locally with explicit inputs and bounded deterministic logic; review assumptions before operational use.
Box Fit Estimator
Box Fit Estimator. Run the workflow locally with explicit inputs and bounded deterministic logic; review assumptions before operational use.
Seller Pack Converter
Seller Pack Converter. Run the workflow locally with explicit inputs and bounded deterministic logic; review assumptions before operational use.
SKU Generator
SKU Generator. Run the workflow locally with explicit inputs and bounded deterministic logic; review assumptions before operational use.
Identifier Checksum Validator
Identifier Checksum Validator. Run the workflow locally with explicit inputs and bounded deterministic logic; review assumptions before operational use.
Accessible Palette Checker
Accessible Palette Checker. Runs a bounded deterministic pre-check locally. Review context and exceptions before treating the result as accessibility evidence.
Target Size Checker
Target Size Checker. Runs a bounded deterministic pre-check locally. Review context and exceptions before treating the result as accessibility evidence.
FPS / Timecode Converter
FPS / Timecode Converter. Bounded deterministic media workflow; review the disclosed method and limitations before production use.
Pallet Layer Utilization Calculator
Estimate uniform carton count and footprint utilization for one pallet layer.
Bleed & Safe-Area Calculator
Calculate trim, bleed and safe-area dimensions from explicit values.
Paper Size Matcher
Compare sheet dimensions with common ISO and North-American paper sizes.
VIN Check-Digit Validator
VIN Check-Digit Validator. Deterministic offline tool with explicit assumptions and bounded scope.
Wheel Offset Calculator
Wheel Offset Calculator. Deterministic offline tool with explicit assumptions and bounded scope.
Gear Ratio / RPM-Speed Calculator
Gear Ratio / RPM-Speed Calculator. Deterministic offline tool with explicit assumptions and bounded scope.
Wire Gauge Calculator
Wire Gauge Calculator. Deterministic offline tool with explicit assumptions and bounded scope.
Resistor Network Calculator
Resistor Network Calculator. Deterministic offline tool with explicit assumptions and bounded scope.
Capacitor Code Decoder
Capacitor Code Decoder. Deterministic offline tool with explicit assumptions and bounded scope.
Inductor Code Decoder
Inductor Code Decoder. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Rebar Weight Calculator
Rebar Weight Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Pipe Volume & Weight Calculator
Pipe Volume & Weight Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Sheet Metal Weight Calculator
Sheet Metal Weight Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Steel Profile Weight Calculator
Steel Profile Weight Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Cutting Yield Calculator
Cutting Yield Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Significant Figures Calculator
Significant Figures Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Uncertainty Propagation Calculator
Uncertainty Propagation Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Molarity & Dilution Calculator
Molarity & Dilution Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Wavelength / Frequency Calculator
Wavelength / Frequency Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Decibel Calculator
Decibel Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.
Torque / Power Calculator
Torque / Power Calculator. Deterministic diagnostic/calculation tool with explicit limits; draft/noindex until final release gates pass.