What is this unit converter?
This tool converts values between the everyday measurement units people actually search for — metres and feet, kilograms and pounds, Celsius and Fahrenheit, litres and gallons, and more. Switch the category tabs above to jump between length, weight, temperature, area, volume, and speed, all using the same simple amount-and-units layout.
How to use it
- Pick a category from the tabs — length, weight, temperature, area, volume, or speed.
- Type the amount you want to convert.
- Choose the unit you're converting from and the unit you want to.
- Hit the round ⇄ button to flip the two units instantly.
- Press Convert, or tap a quick-conversion chip for a common pair.
Good to know
Conversions use standard, internationally recognised conversion factors (for example, 1 inch is exactly 2.54 cm, and 1 pound is exactly 0.45359237 kg), so results are accurate to several decimal places. Temperature uses proper formulas rather than a simple ratio, since Celsius, Fahrenheit, and Kelvin scales don't share a common zero point.
Worked example
Frequently asked questions
One foot equals 30.48 centimetres exactly (12 inches, each exactly 2.54 cm). So 5 feet 10 inches works out to 177.8 cm.
Celsius, Fahrenheit, and Kelvin don't share a common zero point, so you can't multiply by a single ratio the way you can with length or weight. Fahrenheit to Celsius is (F − 32) × 5/9, and Celsius to Kelvin is C + 273.15 — this tool applies the correct formula for whichever pair you pick.
No — a US gallon is about 3.785 litres, while an imperial (UK) gallon is about 4.546 litres, roughly 20% larger. This converter uses the US gallon, which is the standard in American recipes, fuel economy figures, and most conversion requests.
All factors used here are the internationally defined exact values (for example, 1 inch = 2.54 cm and 1 pound = 0.45359237 kg exactly), so results are accurate to several decimal places — any rounding you see is just for display.
Yes — the Speed tab covers metres/second, kilometres/hour, miles/hour, knots, and feet/second, using the same live-as-you-type layout as the other categories.
About & privacy
This converter uses standard, internationally recognised conversion factors, and every calculation happens locally in your browser — the numbers you type are never sent to or stored on our servers. It's one of Convertly's free, ad-supported reference tools; see the full privacy policy for details.