Free Unit Converters for Every Measurement.
See every unit at once.
Length, weight, temperature, volume, area, speed, data storage, time, height and cooking — type one value and read off every unit in the table. All math runs in your browser.
One brand. Four toolboxes.
Everyday converters live here — finance, health and insurance each have their own site with the depth they need.
Finance calculators
Marketplace fees, creator income, business and pricing math — Etsy, eBay, Patreon, YouTube and more.
Health calculators
BMI, calorie, BMR, TDEE and wellness calculators for fitness and everyday healthy-living estimates.
Insurance estimators
Auto, life, home, renters, health and business insurance cost estimates — ballpark premiums by state and profile.
All unit converters
Everyday calculators
Quick math that doesn't need a calculator app — tip splits, percentages, age and dates.
Why use these converters?
Most conversion tools answer one pair at a time — centimeters to inches, then inches to centimeters as a separate search. Every converter here works the other way: you type one value and the whole table updates at once, so you can read off millimeters and miles without touching another field.
The factors are exact definitions rather than rounded constants. An inch is exactly 2.54 cm, a pound is exactly 0.45359237 kg, and a US gallon is exactly 3.785411784 L. Where two systems disagree — US versus UK gallons, decimal gigabytes versus binary gibibytes — both are listed separately instead of quietly picking one.
That last point matters more than it sounds: a US gallon and an imperial gallon differ by 20%, and a 1 TB drive reports as 931 GB for the same reason. Each converter explains the discrepancy rather than hiding it.