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Miles to Kilometers Converter
Convert miles to kilometers — and kilometers back to miles — instantly. Uses the exact factor of 1.609344 km per mile, derived from the international definition of the yard.
mi
1.6093
km
Decimals:
Exact 1.609344 km/mi
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The Conversion Formula
Miles to Kilometers
km = miles × 1.609344
e.g. 10 × 1.609344 = 16.09344 km
Kilometers to Miles
miles = km ÷ 1.609344
e.g. 100 ÷ 1.609344 = 62.137 mi
The factor 1.609344 is exact: 1 yard = 0.9144 m exactly (international definition), 1 mile = 1760 yards, so 1 mile = 1760 × 0.9144 = 1609.344 m = 1.609344 km. No rounding involved.
Common Conversions
| Miles | Kilometers | Note |
|---|---|---|
| 1 mi | 1.6093 | — |
| 2 mi | 3.2187 | — |
| 3 mi | 4.8280 | — |
| 5 mi | 8.0467 | 5K race |
| 10 mi | 16.093 | 10K race |
| 13.1 mi | 21.082 | Half marathon |
| 26.2 mi | 42.165 | Marathon |
| 50 mi | 80.467 | — |
| 100 mi | 160.93 | — |
| 1000 mi | 1609.3 | — |
Unit Facts
- 1 mile = 1.609344 km = 1609.344 m
- 1 mile = 5280 feet = 1760 yards = 63,360 inches
- 1 km = 0.621371 miles
- Miles are used mainly in the US, UK, and a few territories
Running Distances
- 5K race3.107 mi
- 10K race6.214 mi
- Half marathon (21.1 km)13.109 mi
- Marathon (42.195 km)26.219 mi
Frequently Asked Questions
How many kilometers is 1 mile?
1 mile = 1.609344 kilometers exactly. This is derived from the international definition: 1 yard = 0.9144 m, 1 mile = 1760 yards, so 1 mile = 1760 × 0.9144 = 1609.344 m = 1.609344 km.
How do I convert miles to kilometers?
Multiply miles by 1.609344. Example: 5 miles × 1.609344 = 8.0467 km. A quick mental estimate: multiply by 1.6 (slightly under the true value).
Is a mile longer than a kilometer?
Yes. A mile is about 60.9% longer than a kilometer. 1 mile = 1.609344 km, while 1 km = 0.621371 miles. When reading a European road sign in km, divide by 1.6 to get a rough miles equivalent.
How many miles is a marathon?
The official marathon distance is 42.195 km, which equals approximately 26.219 miles (42.195 ÷ 1.609344). It is often cited as "26.2 miles" in the US.
What is 5 miles in kilometers?
5 miles = 8.04672 kilometers (5 × 1.609344). This is often rounded to 8 km in casual contexts, though the exact value is 8.04672 km.
Why is the exact factor 1.609344?
The 1959 International Yard and Pound Agreement defined 1 yard = 0.9144 m exactly. Since 1 mile = 1760 yards: 1 mile = 1760 × 0.9144 m = 1609.344 m = 1.609344 km. The factor is a mathematical consequence of the yard definition — not an independent measurement.