Unit Converter
Convert across 13 categories, from length and weight to data, energy, and pressure.
Convert between metric and imperial units across thirteen categories - length, weight, volume, area, speed, time, data, pressure, energy, power, angle, frequency, and temperature. Meters to feet, kilograms to pounds, gibibytes to megabytes, atmospheres to psi, kilowatt-hours to BTU. Results update instantly as you type, with no ads, signup, or daily limit, whether you are adapting a recipe or reading a spec sheet written in units you don't normally work with.
Runs on your device. This tool processes your file inside this browser tab. Nothing is uploaded, so it also works offline once the page has loaded, and closing the tab discards the file from memory.
Loading tool
How it works
- 01
Pick a category, from length and weight through to data, energy, and frequency.
- 02
Enter a value and choose the source unit.
- 03
Read the converted value in your target unit instantly.
Details
- Category
- Developer & data
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-12
Common questions
Which unit categories are supported?
Thirteen: length, weight, volume, area, speed, time, data, pressure, energy, power, angle, frequency, and temperature - each covering both metric and imperial units where both exist.
How precise are the conversions?
Standard conversion factors are used and results are shown to ten significant figures, switching to scientific notation for very large or very small values such as light years or electronvolts.
Is my input sent anywhere?
No - conversion runs entirely in your browser.
Can I convert cooking measurements like cups to milliliters?
Yes. Volume covers cups, tablespoons, teaspoons, pints, quarts, and fluid ounces alongside metric units. US and UK gallons are listed separately, as are the US customary cup (236.6 ml) and the metric cup (250 ml), so a recipe converts to the measure you actually own.
Can I use this from the API?
Yes - the same conversion tables back the free unit-converter API endpoint, so a script and the web tool always agree.
Use this from your code
This tool is also a REST endpoint, so you can run it in a pipeline instead of by hand. It is free and needs no API key. See the API reference for every parameter.
curl -X POST https://fileoven.com/api/v1/tools/unit-converter \
-H "Content-Type: application/json" \
-d '{"category":"length","from":"m","to":"km","value":255}'