Kilometres to miles
Multiply kilometres by 0.621371 to get miles.
21 km = 13.0488 mi
How to convert kilometres to miles
The mile is exactly 1609.344 metres (5280 feet), the international mile. The kilometre is one thousand metres (10³ m).
Worked example — 21 km: 21 × 0.621371 = 13.0488 mi.
Kilometres to miles table
| Kilometres | Miles |
|---|---|
| 1 km | 0.621371 mi |
| 2 km | 1.2427 mi |
| 5 km | 3.1069 mi |
| 10 km | 6.2137 mi |
| 21 km | 13.0488 mi |
| 42 km | 26.0976 mi |
| 50 km | 31.0686 mi |
| 100 km | 62.1371 mi |
| 200 km | 124.2742 mi |
Reverse and related
About kilometres and miles
Kilometre (km)
1 km = 0.621371 miDefinition. One thousand metres (10³ m)
History and origin
The kilometre, one thousand metres, was defined along with the metric system in the 1790s as its unit for long distances. It spread across the world with the metric system through the nineteenth and twentieth centuries.
Current use
Kilometres are the standard unit for road distances and running races in most of the world; the United States and United Kingdom still post road distances in miles.
Source: BIPM, The International System of Units (SI), 9th ed. (2019)
Mile (mi)
1 mi = 1.6093 kmDefinition. Exactly 1609.344 metres (5280 feet), the international mile
History and origin
The mile comes from the Roman mille passus, a thousand paces, and became the English statute mile of 5280 feet in 1593. Through the 1959 agreement it is exactly 1609.344 metres.
Current use
The mile is the main unit for road distances and speed limits in the United States and United Kingdom, and for running events like the mile and the marathon.
Source: International Yard and Pound Agreement (1959); NIST Handbook 44, App. C
Where people use this
Kilometres: road distances, running races. Miles: road distances in the US and UK, running. A 42.195 km marathon is 26.2 miles.
Every value is carried to full double precision; the display is rounded.
Sources: International Yard and Pound Agreement (1959); NIST Handbook 44, App. C; BIPM, The International System of Units (SI), 9th ed. (2019).
Questions people ask
How many miles is 1 km?
One kilometre is about 0.6214 miles. To convert km to miles, multiply by 0.6214.
How many miles is 5 km?
A 5 km race is about 3.11 miles, and a 10K is about 6.21 miles.
How many miles is a marathon?
A 42.195 km marathon is 26.2 miles; a half marathon is 21.1 km, or 13.1 miles.
How many miles is 100 km?
100 km is about 62.1 miles.
How do you convert km to miles?
Multiply the kilometres by 0.6214. A quick estimate is to take about five eighths of the number.