Free Unit Converter
1 Millimetre (mm) = 0.1 Centimetre (cm)
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About the Unit Converter
Convert between units of length, weight, temperature, volume, area and speed — pick a category and see the result instantly, all in your browser.
How to use the Unit Converter
- 1Pick a category — length, weight, temperature, volume, area or speed.
- 2Choose the unit to convert from and the unit to convert to.
- 3Type a value and read the converted result instantly.
- 4Everything is calculated in your browser — nothing is uploaded.
Frequently asked questions
Is this unit converter free?
Yes — completely free, with no sign-up and no watermark.
Is my data uploaded anywhere?
No. All conversions run in your browser — nothing you enter is sent anywhere.
Which units are supported?
Length (mm to miles), weight (mg to pounds), temperature (Celsius, Fahrenheit, Kelvin), volume (ml to gallons), area (cm² to acres) and speed (m/s, km/h, mph, knots).
Are the US or imperial units exact?
Yes — conversions use the internationally defined exact factors (for example 1 inch = 2.54 cm and 1 pound = 453.59237 g), so results are accurate to the precision shown.
How is temperature converted?
Temperature isn't a simple multiplication because the scales have different zero points, so it's converted through Celsius using the standard formulas — for example °F = °C × 9/5 + 32.