Length Converter
How these units are defined
The metre is the SI base unit, defined by the speed of light. Since the 1959 international yard and pound agreement the imperial and US customary units are defined exactly in metres: 1 yard = 0.9144 m, so 1 foot = 0.3048 m, 1 inch = 2.54 cm and 1 mile = 1,609.344 m.
| Unit | Equals |
|---|---|
| 1 Kilometer | 1,000 Meter |
| 1 Centimeter | 0.01 Meter |
| 1 Millimeter | 0.001 Meter |
| 1 Inch | 0.0254 Meter |
| 1 Foot | 0.3048 Meter |
| 1 Yard | 0.9144 Meter |
| 1 Mile | 1,609.344 Meter |
Worked examples
- 1 Mile = 1.609344 Kilometer
- 5 Mile = 8.04672 Kilometer
- 26.2188 Mile = 42.195068 Kilometer
- 100 Mile = 160.9344 Kilometer
Common mistakes
- Decimal feet are not feet-and-inches: 5.75 ft is 5 ft 9 in, not 5 ft 7.5 in. Split off the whole feet and multiply the remainder by 12.
- A nautical mile (1,852 m) is about 15% longer than a statute mile (1,609.344 m). Knots and sea charts use nautical miles.
- The US survey foot (1200/3937 m) differs from the international foot by 2 parts per million. It was retired from official US use at the end of 2022 but still appears in older land records.
Length conversions
Frequently asked questions
How many feet are in a mile?
There are 5,280 feet in a mile. This is a standard conversion used in the imperial system.
How do I convert kilometers to miles?
To convert kilometers to miles, multiply the number of kilometers by 0.621371. For example, 10 km = 6.21 miles.
What is the difference between metric and imperial length?
Metric uses meters and its derivatives (km, cm, mm), while imperial uses feet, inches, yards, and miles. Metric is based on powers of 10, making conversions simpler.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy