What is kilometre?
A kilometre is a metric unit of length equal to 1,000 metres. It is the standard unit for road distances, route planning, and geographic measurements in most countries.
Real-world uses
Kilometres are the standard unit for road distances, city-to-city navigation, and speed limits in most countries outside the United States. Marathon runners track their pace in minutes per kilometre, and GPS devices report distances in km.
History
Introduced as part of the metric system in France in 1795. The prefix "kilo-" comes from the Greek word "chilioi" meaning thousand. It became the global standard for road distances as the metric system spread in the 19th and 20th centuries.
Common mistakes
Assuming 1 mile equals 1 kilometre—a mile is actually about 1.609 km. Another error is mispronouncing it as "kil-AH-meter" instead of "KIL-o-metre," which changes the implied meaning.
What is mile?
A mile is a unit of length commonly used in the United States and the United Kingdom for road distance and travel-related measurements.
Real-world uses
Miles are used for road distances and speed limits in the United States, the United Kingdom, and a few other countries. Runners track marathon distances in miles (26.2 mi), and car odometers in these countries display miles.
History
The word "mile" comes from the Latin "mille passus" meaning a thousand paces (double steps), roughly 4,860 Roman feet. The statute mile of 5,280 feet was established by English Parliament in 1593 under Queen Elizabeth I.
Common mistakes
Confusing statute miles (5,280 feet) with nautical miles (1,852 metres). Also, assuming that mileage figures (like fuel economy in mpg) translate directly when comparing US gallons versus Imperial gallons.
When is this conversion used?
Converting between kilometre and mile is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region. Road distances and speed limits are posted in kilometres in most countries and miles in the US and UK, making this conversion essential for international drivers and route planning.
Worked examples
1 kilometre = 0.62137119 mile
1 mile = 1,609.344 metre
How to convert kilometre to mile
To convert kilometre to mile, multiply the value by 0.62137119.
To convert mile back to kilometre, multiply by 1.609344.
Measurement standards
The metre is one of seven SI base units, maintained by the International Bureau of Weights and Measures (BIPM). Since 2019, it is defined by fixing the numerical value of the speed of light in vacuum to exactly 299,792,458 metres per second.
Did you know?
A human hair is roughly 70 micrometres wide, while a single gold atom measures about 0.144 nanometres in diameter — meaning you could line up nearly half a million atoms across the width of one hair.
Quick reference: kilometre to mile
| kilometre | mile |
|---|---|
| 0.1 | 0.06213712 |
| 0.5 | 0.3106856 |
| 1 | 0.62137119 |
| 2 | 1.24274238 |
| 5 | 3.10685596 |
| 10 | 6.21371192 |
| 25 | 15.53427981 |
| 50 | 31.06855961 |
| 100 | 62.13711922 |
| 250 | 155.34279806 |
| 500 | 310.68559612 |
| 1,000 | 621.37119224 |
Common values
| kilometre | mile | |
|---|---|---|
| Height of a door | 0.0021 kilometre | 0.00130488 mile |
| Basketball court length | 0.028 kilometre | 0.01739839 mile |
| Football field (soccer) | 0.105 kilometre | 0.06524398 mile |
| Marathon distance | 42.195 kilometre | 26.21875746 mile |
| Altitude of a cruising airplane | 10.668 kilometre | 6.62878788 mile |