Math

Unit converter.

Convert length, weight, volume, temperature, area, speed, data and time — instantly.

Metric and imperial, both ways

This converter covers the units that come up most — kilometres and miles, kilograms and pounds, litres and gallons, Celsius and Fahrenheit — across eight categories. Everything is calculated locally as you type, so it's instant and works offline once the page has loaded. A note on the "data" category: it uses binary sizes (1 kilobyte = 1024 bytes), which is how operating systems usually report file sizes. For kitchen-specific measures and ingredient weights, the cooking conversions page is purpose-built; for mental shortcuts, see mental math.

FAQ

How many kilometres are in a mile?
1 mile is 1.609 kilometres, and 1 kilometre is about 0.621 miles. A quick mental estimate: multiply miles by 8 and divide by 5 to get kilometres.
Does the converter work offline?
Yes — all conversions run in your browser with no server, so once the page has loaded it keeps working without a connection.

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