miles to km formula
To convert miles to kilometers, multiply the number of miles by 1.609344. In symbols: km = mi × 1.609344.
One mile equals 1.609344 kilometers, and one kilometer equals 0.621371192237 miles. The international mile is exactly 1,609.344 meters, so 1 mile is exactly 1.609344 km.
Worked example
Suppose you have 26.2 miles and need the answer in kilometers.
- Write the formula: km = mi × 1.609344.
- Put in the number: 26.2 × 1.609344 = 42.1648128.
- Round to suit the job. 42.16 km is accurate enough for most everyday uses.
So 26.2 mi is 42.1648128 km. To check, convert back: 42.1648128 km is 26.2 mi.
Common miles to kilometers values
| miles (mi) | kilometers (km) |
|---|---|
| 1 | 1.609344 |
| 2 | 3.218688 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 20 | 32.18688 |
| 50 | 80.4672 |
| 100 | 160.9344 |
Reference points
Some familiar amounts in miles, converted to kilometers:
- 1 mi, a short walk: 1.60934 km
- 3.1 mi, a 5K race: 4.98897 km
- 26.2 mi, a marathon: 42.1648 km
- 250 mi, a typical day of driving: 402.336 km
Where you will use it
Road signs, car trips, running races and mileage rules use miles in the US and UK, while maps and most countries use kilometers. Marathon and 10K results are quoted in both.
Quick mental math
Multiply by 1.6 for an estimate. A neat trick: miles to km follows the Fibonacci steps 5, 8, 13, 21 closely. Rule of thumb: multiply by 1.6. For 26.2 mi this gives 41.92 km against the exact 42.16, an error of 0.58 percent.
Going the other way
Need the reverse? Use the km to miles converter. For comparison, 1 km is 0.62137119 mi. To compare every length unit at once, open the length converter.
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