How to convert units
- Pick a category, then choose which units to convert between.
- Type a value; the result updates as you type.
- Use Swap units to reverse the direction.
Temperature uses the exact Celsius, Fahrenheit, and Kelvin formulas, shown on screen as you convert.
Unit Converter
Convert between units in 10 categories - length, weight, temperature, area, volume, time, speed, pressure, energy, and data. One button swaps the from and to units, so you can reverse a conversion without retyping the value.
Your recent conversions are kept in this browser so you can glance back at them, and you can clear the list at any time. Everything runs in your browser - there is no upload and no account, and your numbers never leave the page.
Read the guide: How to Convert Units Online - Free, No Sign-Up
Frequently Asked Questions
Which unit categories can I convert between?
Ten: length, weight, temperature, area, volume, time, speed, pressure, energy, and data. Choose a category first and the From and To lists fill with the units available in it.
How do I reverse a conversion?
Press the Swap units button. It exchanges the From and To units, moves the current result into the value box, and recomputes in place, so you do not retype anything.
Are the temperature conversions exact?
Yes. Celsius, Fahrenheit, and Kelvin convert through the standard offset formulas rather than a single multiplier, and the active formula is printed beneath the result so you can check the maths.
How precise are the results?
Results show 6 significant digits. Whole numbers stay as integers, and very small magnitudes (below one millionth) switch to exponential notation so the figure is not rounded away to zero.
Where are my recent conversions stored?
Only in this browser, and they stay there until you clear them. There is no account and no cross-device sync, so the list will not follow you to another device or browser.
Can it convert currencies?
No. This tool handles physical units only and carries no live exchange rates. It also does not cover fuel economy, cooking portions, or astronomical units beyond those in the ten categories.
How are a month and a year measured in the time category?
By average length - a month is 30.44 days and a year is 365.24 days. These are not tied to a specific calendar month or leap year.
What happens if I type something that is not a number?
The result clears and an inline message asks for a valid number. Clearing the value box on its own just empties the result without showing the message.