Unit Converter
Convert between units of length, weight, temperature, volume, area, speed, time and digital storage.
1 Millimetre (mm) =
0.1 cm
Centimetre (cm)
Metre (m)0.001
Kilometre (km)0.000001
Inch (in)0.03937
Foot (ft)0.003281
Yard (yd)0.001094
Mile (mi)0.000000621
Nautical mile0.00000054
All other units in this category are shown above for the same input value.
About the Unit Converter
Pick a category, choose the units on each side, and the conversion updates as you type. Every common metric and imperial unit is covered across eight categories, with temperature handled by its own offset formulas rather than simple ratios.
Formula
Most units convert through a base unit: the input is multiplied by its factor to reach the base, then divided by the target unit's factor. Temperature is the exception, since Celsius, Fahrenheit and Kelvin have different zero points as well as different scales.
Frequently Asked Questions
One kilogram is exactly 2.20462262 pounds. For quick mental maths, doubling the kilograms and adding ten percent gets you within half a percent.
Multiply by 9/5 and add 32. So 20°C becomes 20 × 1.8 + 32 = 68°F. The two scales meet at −40, where both read the same number.
They descend from different historical standards. A US liquid gallon is 3.785 litres while an imperial gallon is 4.546 litres — about 20% larger — which also makes US and UK pints and fluid ounces differ.
Both are in use. Storage manufacturers use 1000, while operating systems typically use 1024. This converter uses 1024, which is why a drive sold as 1 TB shows as roughly 931 GB.
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