Convert anything.
Instantly.
— units, 9 categories, zero friction. The answer appears before you've even finished typing.
Tip: press / to search · Enter to copy the result
A category for every part of life
Cooking, travel, fitness, work… Click, convert, get on with your day.
The two-way converter
Edit one side, the other follows. Switch units on the fly, swap with one click.
Every conversion you'll ever need
One click away — no sign-up, no limits, always free.
Straight answers, no fluff
Is CalculUnits really free?
Yes, 100%. Unlimited conversions, no account, no hidden paywall. The site is funded by non-intrusive ads — that's it.
Why are there ads?
Ads keep CalculUnits completely free for everyone. They're placed so they never get in the way of your conversions.
Where do the conversion factors come from?
From official references (SI, NIST). All calculations run in your browser: no data ever leaves your device.
How does natural-language search work?
Type a value and units, with or without “to”: “5 miles to km”, “180 lb”… Units are detected automatically and the result appears instantly.