Unit Converter
Free unit converter with exact, standards-based factors — length, weight, temperature, area, volume, speed, time, digital storage, pressure, energy, power, angle, fuel economy and more. Swap, copy and see the formula.
Unit Converter — Convert Between Any Measurement Unit Instantly
Kilometres to miles. Kilograms to pounds. Celsius to Fahrenheit. Litres to gallons. Acres to square metres. Whether you are cooking with a foreign recipe, interpreting international shipping dimensions, or working on an engineering project, unit conversions come up constantly — and a small error in the factor becomes a big error at scale. This converter uses the exact figures.
Fifteen categories — length, weight, temperature, area, volume, speed, time, digital storage, data transfer rate, pressure, energy, power, angle, fuel economy and number scale — with the answer as you type, a one-tap swap, a copy button, the formula shown, and every related unit listed at a glance. No signup, no cost.
Accuracy is the whole point of a converter
- Exact, standards-based factors. A mile is 1609.344 m, not 1609.34. A pound is 0.45359237 kg. An acre is 4046.8564224 m². A US gallon is 231 cubic inches. These are the legal definitions, carried to full double precision — not the rounded-off constants many converters quietly use.
- Fuel economy is done properly. km/L and mpg are the reciprocal of L/100km, not a simple scaling — a mistake that trips up naive converters. 10 km/L is 23.52 US mpg, and the maths goes through consumption to get there.
- SI and binary storage are kept separate. 1 GB is 1,000,000,000 bytes; 1 GiB is 1,073,741,824. Conflating them is why your "500 GB" drive shows as 465 GB.
- No display lies. The old habit of printing every result to six decimals turned a nanometre into "0.000000" — i.e. zero. Here small and large values switch to scientific notation and nothing silently rounds to nothing.
- Regionally variable units are left out on purpose. A bigha is anywhere from 1,500 to 27,000 sq ft depending on the state, so publishing a single number would be wrong for most people. Every unit here has one unambiguous, standard value.
How to Convert Units
1. Choose Category
Tap one of the fifteen chips — length, weight, temperature, area, volume, speed, time, digital storage, data transfer, pressure, energy, power, angle, fuel economy or number scale.
2. Enter Value
Type the number and pick the From and To units. The result appears instantly, and you can paste figures with commas.
3. Swap or Compare
Reverse the conversion with the swap button, or read the value in every unit of the category in the table below — tap any row to convert into it.
4. Copy or Verify
Copy the result with one tap, set the precision from 4 significant figures up to full, and check the formula shown under the answer.
Supported Unit Categories
Length
Millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, nautical miles, and more.
Weight
Micrograms to tonnes, ounces, pounds, stones, US and UK tons, grains, carats — plus Indian tola and masha and the quintal.
Temperature
Celsius, Fahrenheit, Kelvin, Rankine and Réaumur, through the absolute scale so the anchors are exact — 100°C is exactly 212°F, with the formula displayed.
Volume
Millilitres, litres, cubic metres and feet, teaspoons, tablespoons, cups, pints, quarts and gallons in both US and UK measures — which are genuinely different sizes.
Digital & Data Rate
Bits and bytes, KB to PB in both SI (1000) and binary (1024) — KiB, MiB, GiB, TiB — plus bit/s and byte/s transfer rates.
Engineering
Speed, pressure (Pa, bar, psi, atm, mmHg), energy (J, cal, kWh, BTU), power (W, hp, PS) and angle (degrees, radians, gradians).
Fuel & Number Scale
Fuel economy across km/L, L/100km and mpg (US and UK), plus the Indian number scale — thousand, lakh, crore, million, billion, arab.
Free and Private
No signup, no tracking. Runs entirely in your browser with instant results.