Conversion Result
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Miles (mi)
About This Converter
- What it does
- Converts kilometers to miles with reverse conversion.
- Input
- Distance in kilometers (km)
- Output
- Miles (mi); reverse km value
- Formula
- miles = km × 0.621371 (since 1 mi = 1.609344 km exactly)
- Last updated
About Kilometers to Miles Conversion
Kilometers and miles are the two most common units for measuring road distances and travel speeds. Kilometers are the international standard, used across Europe, Asia, Africa, and most of the world. Miles are used in the United States, the United Kingdom (on roads), and a few other countries. Converting between them is a daily need for travelers, runners, and anyone comparing car performance across regions.
Conversion Formula
miles = km × 0.621371
One mile equals exactly 1609.344 meters = 1.609344 km. Therefore, 1 km = 1 ÷ 1.609344 = 0.621371 miles. Multiply kilometers by 0.621371 for miles; multiply miles by 1.609344 for km.
Worked Example
A marathon is 42.195 km. 42.195 × 0.621371 = 26.219 miles — the standard marathon distance of 26.2 miles.
Common Use Cases
- Road trips in Europe: converting distances between cities from km to miles for US visitors
- Running and cycling: a 10 km race = 6.214 miles; a 100 km ride = 62.14 miles
- Speed conversion: 100 km/h speed limit ≈ 62.1 mph
- Car specifications: fuel economy in L/100km vs mpg — first step is km to miles
- Comparing map scales between metric and imperial countries for hiking or navigation
Frequently Asked Questions
1 km = 0.621371 miles, or about 5/8 of a mile.
5 × 0.621371 = 3.107 miles.
10 × 0.621371 = 6.214 miles.
100 × 0.621371 = 62.137 miles.
1 mile = 1.609344 km exactly.
26.2 × 1.609344 = 42.165 km ≈ 42.2 km. The exact IAAF marathon distance is 42.195 km.
Multiply km by 0.6 (or 3/5) for a close estimate. Example: 50 km × 0.6 = 30 miles (exact: 31.07 miles). For better accuracy, multiply by 5/8 = 0.625.
60 × 0.621371 = 37.28 mph. Common conversions: 50 km/h ≈ 31 mph, 100 km/h ≈ 62 mph, 120 km/h ≈ 75 mph.
Important Notes
- 1 mile = 1.609344 km exactly (international definition).
- 1 km = 0.621371 miles — slightly less than 5/8 mile.
- A 5 km run ≈ 3.107 miles; a half marathon is 21.0975 km = 13.109 miles.
- Speed units (km/h to mph) use the exact same conversion factor.