Length Converter

How to use the length Converter

1. Enter the value.
2. Choose the from from the list.
3. Choose the to from the list.
4. The result updates instantly as you type. There is no button to press.
5. Use Copy result to copy the figures, or Copy link to share a link that reopens the length Converter with the same inputs.

How it works

Length is the most common measurement to convert, and the one where two systems collide most often: the metric system, used by almost every country and by science, and the imperial and US customary units still used for everyday measurements in the United States and, for some things like height and road distances, in the UK.

The two systems have been tied together exactly since the 1959 international yard and pound agreement, which defined the inch as exactly 2.54 centimetres. Every other imperial length follows from that: a foot is 12 inches (30.48 cm), a yard is 3 feet (0.9144 m) and a mile is 1,760 yards (1,609.344 m). The nautical mile, used in aviation and at sea, is defined as exactly 1,852 metres, based roughly on one minute of latitude.

This converter changes your value to metres first, then from metres to the unit you want, and shows the result in every unit at once. For heights and room sizes, it also shows the result in feet and inches. Results are displayed to 10 significant figures, so they are exact for all practical purposes.

Formula

Example

To convert 10 km to miles: 10 × 1,000 = 10,000 m, and 10,000 ÷ 1,609.344 = 6.2137 miles, the distance of a 10K race. A height of 175 cm is 175 ÷ 2.54 = 68.9 inches, or 5 ft 8.9 in. A 6-foot person is 6 × 30.48 = 182.88 cm tall.

Frequently asked questions