Convert Kilometers (km) to Miles (mi)
1 kilometer equals 0.621371 miles.
Kilometer to Mile Converter
What Is a Kilometer?
The kilometer (km) is a metric unit of length equal to 1,000 meters. It is the global standard for road distances and is used by most countries for speed limits, navigation, and athletics. One kilometer ≈ 0.621 miles.
What Is a Mile?
The mile (mi) is a unit of length in the US customary and British imperial systems, defined as exactly 5,280 feet (1.609344 km). It remains the standard for road distances in the US, UK, and a few other countries.
Kilometers to Miles Formula
The conversion factor derives from the exact mile definition:
miles = kilometers × 0.621371 exact
This is the reciprocal of 1.609344: 1/1.609344 ≈ 0.621371 mi per km.
Worked Example
Convert 10 km (a common race distance) to miles:
- Multiply: 10 × 0.621371 = 6.214 miles
So a 10K race = 6.21 miles. A 5K = 3.11 miles. A marathon (42.195 km) = 26.2 miles.
Quick Estimation
For mental math, multiply km by 0.6 (undershoots by 3.4%). Better: multiply by 5 and divide by 8. Example: 100 km × 5 ÷ 8 = 62.5 miles (exact: 62.14). The Fibonacci trick also works: 8 km ≈ 5 mi, 13 km ≈ 8 mi (consecutive Fibonacci numbers).
Common Use Cases
- Driving in the US/UK: GPS showing 150 km to destination means about 93 miles. Speed limit of 120 km/h = 74.6 mph.
- Running events: 5K = 3.1 mi, 10K = 6.2 mi, half marathon (21.1 km) = 13.1 mi.
- Travel planning: European road signs in km; US travelers need mile equivalents for time estimates.
- Automotive: Odometers in rental cars abroad may show km. 100,000 km = 62,137 miles.
Frequently Asked Questions
How many miles is 1 kilometer?
1 km = 0.621371 miles. A kilometer is about 62% of a mile, or roughly five-eighths.
What is a simple trick to convert km to miles?
Multiply by 5 and divide by 8. Or use Fibonacci: 8 km ≈ 5 mi, 13 km ≈ 8 mi, 21 km ≈ 13 mi. Each pair approximates the 0.621 ratio.
How far is 100 km in miles?
100 km = 62.14 miles. At highway speed (100 km/h ≈ 62 mph), this takes about 1 hour.
Why does the Fibonacci sequence work for km-to-miles?
The ratio of consecutive Fibonacci numbers approaches the golden ratio (1.618), which is very close to the km/mi ratio (1.609). So each Fibonacci number in km ≈ the previous number in miles.
Common Kilometer to Mile Conversions
| Kilometer | Mile | Actions |
|---|---|---|
| 1 kilometer | 0.621371 miles | |
| 2 kilometers | 1.24274 miles | |
| 5 kilometers | 3.10686 miles | |
| 10 kilometers | 6.21371 miles |
| Kilometer | Mile | Actions |
|---|---|---|
| 20 kilometers | 12.4274 miles | |
| 42 kilometers | 26.0976 miles | |
| 100 kilometers | 62.1371 miles |
Kilometers to miles Conversion Table
Reference table with common kilometers to miles conversions. All values calculated with high precision.
Kilometers to Miles Table
0.001 to 5
Kilometers to Miles Table
10 to 1000000
Miles to Kilometers Table
0.0001 to 12
Miles to Kilometers Table
1 to 100000
Looking for the reverse? Convert Mile to Kilometer
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