Kilometers to Miles
Type a value in either box to convert between kilometers and miles. The factor is 0.621371.
| Kilometers | Miles |
|---|---|
| 1 km | 0.621371 mi |
| 2 km | 1.242742 mi |
| 3 km | 1.864114 mi |
| 5 km | 3.106856 mi |
| 10 km | 6.213712 mi |
| 25 km | 15.53428 mi |
| 50 km | 31.06856 mi |
| 100 km | 62.137119 mi |
How to use
- Enter a value in the Kilometers field.
- The Miles figure appears immediately — no button to press.
- Typing in the Miles field converts back to Kilometers the same way.
- Use the reference table for the values that come up most often.
Kilometers to Miles formula
To convert kilometers to miles, multiply by 0.621371192.
mi = km × 0.621371192
Why this factor: the kilometer and the mile are both defined against the meter, so dividing one definition by the other gives 0.621371192 directly. Both definitions are set out in full below.
To go the other way, divide by 0.621371192 — or use the Miles to Kilometers converter, which is the same calculation reversed.
Worked example
Given 5 km, multiplying by 0.621371192 yields 3.106856 mi.
5 km × 0.621371192 = 3.106856 mi
The converter above does this for any value you type, in either direction.
What is a kilometer?
A kilometer is 1,000 meters, the standard unit for road distances and geography in most of the world.
Definition: Exactly 1,000 meters by SI prefix definition — 'kilo' means 10³.
Where it is used: Road signs, running and cycling distances, and map scales outside the US and UK.
What is a mile?
The statute mile is the standard long-distance unit in the United States and the United Kingdom.
Definition: Defined as 5,280 feet, which since the 1959 International Yard and Pound Agreement makes it exactly 1,609.344 meters.
Where it is used: US and UK road signs, speed limits, running races, and vehicle odometers.
Worth knowing: Distinct from the nautical mile (1,852 m), which is about 15% longer and used at sea and in the air.
Kilometers vs Miles
The kilometer is a metric unit while the mile is an imperial unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many miles are in a kilometer?
One kilometer equals 0.621371192 miles.
What is the formula to convert kilometers to miles?
Multiply the number of kilometers by 0.621371192. To reverse it, divide by 0.621371192 instead.
How do I convert miles back to kilometers?
Divide by 0.621371192, which is the same as multiplying by 1.609344.
How many miles are in 10 kilometers?
10 km works out to 6.213712 mi.
Is there anything to watch out for with miles?
Distinct from the nautical mile (1,852 m), which is about 15% longer and used at sea and in the air.
How is the kilometer defined?
Exactly 1,000 meters by SI prefix definition — 'kilo' means 10³.