kilometre (km)
1 kilometre = 1,000 metres
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.
Notes: Metric unit
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.
When is this conversion used?
This conversion is frequently needed in construction, architecture, and real estate where building codes may specify dimensions in one system while materials are sold in another. 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.
How to convert kilometre to metre
To convert kilometre to metre, multiply the value by 1,000.
Conversion formula (from base unit)
x * 1000.0
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.
| kilometres | metres |
|---|---|
| 0.1 | 100 |
| 0.5 | 500 |
| 1 | 1,000 |
| 2 | 2,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 25 | 25,000 |
| 50 | 50,000 |
| 100 | 100,000 |
| 250 | 250,000 |
| 500 | 500,000 |
| 1,000 | 1,000,000 |
Common values
| kilometres | metres | |
|---|---|---|
| Height of a door | 0.0021 kilometres | 2.1 metres |
| Basketball court length | 0.028 kilometres | 28 metres |
| Football field (soccer) | 0.105 kilometres | 105 metres |
| Marathon distance | 42.195 kilometres | 42,195 metres |
| Altitude of a cruising airplane | 10.668 kilometres | 10,668 metres |
Full kilometre conversion table
| Unit | Value | Factor |
|---|---|---|
| metre | 1 km = 1,000 m | × 1,000 |
| centimetre | 1 km = 100,000 cm | × 100,000 |
| millimetre | 1 km = 1,000,000 mm | × 1,000,000 |
| inch | 1 km = 39,370.07874016 in | × 39,370.07874016 |
| foot | 1 km = 3,280.83989501 ft | × 3,280.83989501 |
| mile | 1 km = 0.62137119 mi | × 0.62137119 |
| yard | 1 km = 1,093.61329834 yd | × 1,093.61329834 |
| micrometre | 1 km = 1.000000e+09 µm | × 1.000000e+09 |
| nanometre | 1 km = 1.000000e+12 nm | × 1.000000e+12 |