Unit Converter
Eleven categories, a hundred-plus units, instant conversion.
Runs entirely in your browser
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Same value in every unit
Pick a category, pick two units, type a number. Conversion happens against each category's SI base unit, so every pair inside a category is consistent and round-trips exactly. Converting kilograms to metres is refused rather than quietly answered.
Temperature is the awkward one: Celsius and Fahrenheit have offsets as well as scale factors, which is why 0 °C is 32 °F but 0 °C is not zero of anything. The conversion here handles the offsets properly, including Rankine.
How to use it
- Choose a category such as Length or Temperature.
- Pick the unit you have and the unit you want.
- Type the value. The result updates as you type, and one button swaps the pair.
Questions
Which gallon is used?
US liquid gallon by default (3.785 L); the imperial gallon (4.546 L) is a separate entry in the list. They differ by about 20%, which is why the label always says which one.
Are KB and KiB the same?
No. A kilobyte is 1000 bytes and a kibibyte is 1024. Storage manufacturers use the first, operating systems often use the second, which is why a '1 TB' drive shows as 931 GB. Both are in the list.
How precise are the results?
Conversions use exact factors where one exists (an inch is exactly 25.4 mm) and double-precision arithmetic throughout, then display up to ten significant digits.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. There is no server. You can load this page once, go offline, and it still works.