Don's Tools · Converters · Unit Converter

Unit converter

Convert length, weight, temperature, speed, area, volume, time and data in one place. Type a value in any unit and every other unit updates instantly, all in your browser.

Unit Converter handles all the everyday measurement conversions in one place, covering length, weight, temperature, speed, area, volume, time and data sizes. Choose a category, type a value into any unit, and every other unit updates instantly using standard conversion factors, with metric, US and imperial units side by side. Temperatures use their proper formulas, and everything is calculated in your browser with nothing uploaded.

Frequently asked questions

Is anything uploaded or saved?

No. Every conversion is simple maths done instantly in your browser. Nothing you type is sent anywhere or stored.

What can it convert?

Length, weight, temperature, speed, area, volume, time and data sizes. Pick a category at the top, type a value in any unit, and all the other units update at once.

How accurate are the conversions?

They use standard internationally agreed factors, so they are accurate for everyday and most professional use. Results are shown to several significant figures.

Does it handle US and metric units together?

Yes. Each category mixes metric and US or imperial units, such as miles with kilometres or US gallons with litres, so you can convert straight between them.

Why are temperatures handled differently?

Temperature scales have different starting points, not just different sizes, so Celsius, Fahrenheit and Kelvin are converted with their proper formulas rather than a single multiplier.