Miles to Kilometers
An instant miles-to-kilometers converter, with the formula and a reference table below.
| Miles | Kilometers |
|---|---|
| 1 mi | 1.609344 km |
| 2 mi | 3.218688 km |
| 3 mi | 4.828032 km |
| 5 mi | 8.04672 km |
| 10 mi | 16.09344 km |
| 25 mi | 40.2336 km |
| 50 mi | 80.4672 km |
| 100 mi | 160.9344 km |
How to use
- Enter a value in the Miles field.
- The Kilometers figure appears immediately — no button to press.
- Typing in the Kilometers field converts back to Miles the same way.
- Use the reference table for the values that come up most often.
Miles to Kilometers formula
Converting miles to kilometers is a single multiplication by 1.609344.
km = mi × 1.609344
Why this factor: the mile and the kilometer are both defined against the meter, so dividing one definition by the other gives 1.609344 directly. Both definitions are set out in full below.
To go the other way, divide by 1.609344 — or use the Kilometers to Miles converter, which is the same calculation reversed.
Worked example
Start with 100 mi. Multiply by 1.609344 to get 160.9344 km.
100 mi × 1.609344 = 160.9344 km
The converter above does this for any value you type, in either direction.
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.
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.
Miles vs Kilometers
The mile is an imperial unit while the kilometer is a metric 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 kilometers are in a mile?
One mile equals 1.609344 kilometers.
What is the formula to convert miles to kilometers?
Multiply the number of miles by 1.609344. To reverse it, divide by 1.609344 instead.
How do I convert kilometers back to miles?
Divide by 1.609344, which is the same as multiplying by 0.621371192.
How many kilometers are in 10 miles?
10 mi works out to 16.09344 km.
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 mile defined?
Defined as 5,280 feet, which since the 1959 International Yard and Pound Agreement makes it exactly 1,609.344 meters.