Metric ⇄ Imperial Unit Converter
Convert length, weight, volume, and temperature between metric and imperial units instantly. Runs entirely in your browser — nothing you type is ever uploaded.
What can you convert?
UnitFlip switches between metric and imperial (and US customary) units across four everyday categories: length (millimeters through miles), weight (grams through stone), volume (milliliters through gallons), and temperature (Celsius, Fahrenheit, Kelvin). Pick a category, enter a value, and choose the units on either side — the result updates as you type.
How it works
Every conversion runs directly in your browser using standard, internationally-defined conversion factors — nothing is sent to a server, so it works even offline once the page has loaded. Use the swap button to flip the from/to units without retyping your value.
Frequently asked questions
Is this free to use?
Yes. There's no sign-up and no limit on how many conversions you run.
Do you store what I type?
No. Every conversion happens entirely client-side in your browser. See the privacy policy for details.
How accurate are the conversions?
Conversions use standard internationally-defined conversion factors (for example, 1 inch = 2.54 cm exactly) and are precise to 6 significant figures.
Which units are supported?
Length, weight/mass, volume, and temperature, covering the most common metric and US customary/imperial units.