Km to mi conversion formula
The kilometer (km) is a metric unit of length equal to 1,000 meters — the standard for road distances almost everywhere in the world.
The mile (mi) is an imperial unit of length defined as exactly 1,609.344 meters. It is the standard road-distance unit in the United States and the United Kingdom.
Km to mi conversion table
| km | mi |
|---|---|
| 1 km | 0.621371 mi |
| 2 km | 1.2427 mi |
| 3 km | 1.8641 mi |
| 5 km | 3.1069 mi |
| 10 km | 6.2137 mi |
| 20 km | 12.4274 mi |
| 25 km | 15.5343 mi |
| 50 km | 31.0686 mi |
| 100 km | 62.1371 mi |
| 250 km | 155.3428 mi |
| 500 km | 310.6856 mi |
| 1000 km | 621.3712 mi |
How to convert km to mi
- Write down the value in km you want to convert.
- Multiply it by 0.621371 — or use the converter above, which does it instantly.
- Read your result in mi. Done.
Real-world examples
- A 5K fun run is 3.1 miles — the gateway race for millions of new runners.
- The 10K is 6.2 miles; the half marathon, 21.1 km, is 13.1 miles.
- Paris to Amsterdam by car: 430 km — 267 miles, about four London–Birmingham legs.
- Mount Everest stands 8,849 m tall — 5.5 miles above sea level, near small-jet cruising altitude.
Common mistakes
The mirror error of the miles-to-km page: dividing when you should multiply. 100 km is 62 miles, not 160 — the kilometer is the smaller unit, so the mile number is always smaller. Second trap: swimmers' “metric mile” is 1,500 m, not 1,000 — and certainly not 1,609 m. If a swimmer says “I swam a mile”, ask which one: pool traditions make the same word three distances.
Quick mental conversion
The classic: divide by 5, multiply by 3 (that's ×0.6). 50 km → 10 × 3 = 30 miles (exact: 31.1 — the trick runs ~3% low; add a unit past 50 km). Fibonacci works in this direction too: 8 km ≈ 5 miles, 13 ≈ 8, 21 ≈ 13. Driver's anchor: 100 km ≈ 62 miles.
Frequently asked questions
How many mi is 1 km?
Using the official conversion factor, 1 kilometer = 0.621371 mile. The converter above handles any value instantly.
What is the formula to convert kilometer to mile?
1 kilometer = 0.621371 mile. Multiply any value in km by this factor to get mi.
Is this km to mi converter free?
Yes — 100% free, unlimited, with no sign-up. CalculUnits is funded by non-intrusive ads, never by paywalls.