Convert any length unit
Pick any two units and convert between them: metric lengths (millimetres to kilometres), imperial lengths (inches to miles) and nautical miles. The result updates as you type.
Every unit is defined against the metre. The inch, foot, yard and mile are defined exactly in metres by the 1959 international agreement, so conversions between metric and imperial units are exact.
Units at a glance
| Unit | Symbol | Size |
|---|---|---|
| millimetres | mm | 1 millimetre = 0.001 metres |
| centimetres | cm | 1 centimetre = 0.01 metres |
| metres | m | The base unit for length. |
| kilometres | km | 1 kilometre = 1,000 metres |
| inches | in | 1 inch = 0.0254 metres |
| feet | ft | 1 foot = 0.3048 metres |
| yards | yd | 1 yard = 0.9144 metres |
| miles | mi | 1 mile = 1,609.344 metres |
| nautical miles | nmi | 1 nautical mile = 1,852 metres |
Statute miles and nautical miles
A statute mile is 1,609.344 m and is what road signs in the UK and US show. A nautical mile is exactly 1,852 m, was originally one minute of latitude, and is used at sea and in the air.
Feet and inches
Heights are usually quoted in feet and inches. Convert the inches to a decimal fraction of a foot first (divide by 12), or use the dedicated metres to feet and centimetres to inches pages, which show feet and inches directly.