Length Converter
Convert between metres, feet, inches, miles, kilometres and more.
What the Length Converter does
Length conversion multiplies by a fixed ratio. The metric system scales by powers of ten, while imperial units use historical ratios — 12 inches to a foot, 3 feet to a yard, 5,280 feet to a mile. One inch is defined as exactly 2.54 cm.
Formula
Convert to metre, then divide by the target unit's factorResult = Value × (from factor ÷ to factor)
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Value | number | Yes | — |
| From | one of 12 options | Yes | — |
| To | one of 12 options | Yes | — |
How to use it
- Choose From and To.
- Enter Value.
- Select Calculate.
Worked example
Convert 5 metres to feet.
- Value
- 5
- From
- Metre
- To
- Foot
5 ÷ 0.3048 = 16.4042 feet.
Reading the result
- An inch is defined as exactly 2.54 cm, so imperial-to-metric length conversions are exact rather than approximations.
- A nautical mile is 1,852 m, one minute of latitude, which is why sea and air navigation use it instead of the statute mile.
Common mistakes
- Confusing nm as nanometre with nmi as nautical mile. The two differ by twelve orders of magnitude.
- Assuming the US survey foot and the international foot are the same. They differ by two parts per million, which accumulates over surveying distances.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 cm. This has been the international definition since 1959.
What is a nautical mile?
Exactly 1,852 metres, originally one minute of latitude. It is used in sea and air navigation.