Unit Converter

Convert between units of length, weight, temperature, volume, area, speed, and digital storage — instantly and accurately. Pick a category, choose your two units, and type a value; the result appears as you type, and a swap button flips the direction in one click.

Whether you're following a recipe in the wrong units, checking a package weight, or sizing a room, a reliable converter saves you from second-guessing a mental estimate.

Metric and imperial in one place

Most of the world uses the metric system, but imperial units persist in the United States and in specific trades everywhere. That mismatch is exactly where conversions go wrong. This tool keeps both systems side by side for every category — metres and feet, kilograms and pounds, litres and gallons, Celsius and Fahrenheit — so you can move between them without looking up a factor. Each conversion uses standard, exact ratios (for example, one inch is precisely 2.54 centimetres), so the results are accurate rather than rounded approximations.

Why temperature is different

Most conversions are simple multiplication: to go from kilometres to miles you multiply by a fixed factor. Temperature is the exception, because its scales don't share a zero point. Converting Celsius to Fahrenheit isn't just scaling — you multiply by 9/5 and add 32, because 0°C equals 32°F, not 0°F. Kelvin adds another offset entirely. This converter handles those offsets for you, so switching between Celsius, Fahrenheit, and Kelvin gives the correct value rather than a naive multiplication.

Everyday conversions people look up most

A handful of conversions come up again and again. Cooks convert between millilitres, cups, and fluid ounces, and between grams and ounces, when following recipes written for another country. Travellers switch kilometres and miles for distances and Celsius and Fahrenheit for the weather. DIY and craft projects mix centimetres, inches, and feet. Fitness and health contexts move between kilograms, pounds, and stones. Because this converter keeps every category a click apart and remembers no state between them, you can jump from a kitchen measurement to a travel distance without hunting for a different tool each time.

Precision, rounding, and everyday accuracy

Conversions carry rounding, and where you round changes the answer. Converting 5 kilometres to miles gives 3.106856…, and trimming that to 3.1 is fine for a run but not for engineering tolerances. Temperature is the odd one out: unlike length or mass it isn't a simple ratio, because the Celsius and Fahrenheit scales start at different zero points, so the tool applies the correct offset formula rather than a single multiplier. For anything that must be exact — a recipe, a dosage, a machined part — keep more decimal places than you think you need and round only at the very end.

Frequently asked questions

Last updated: 2026-01-20