miles to kilometres converter
1 mi = 1.609344 km. Type a value in either box — the other side updates instantly, using the exact definition factor, not a rounded shortcut. US and UK road signs count miles; almost everywhere else counts kilometres. The mile is defined as exactly 1.609344 km.
Rate: 1 mi = 1.609344 km · 1 km = 0.6213711922 mi
Formula and a worked example
kilometres = miles × 1.609344. Worked example: 26.2 mi × 1.609344 = 42.164813 km. To go back, divide by the same factor (or multiply by 0.6213711922).
Where the factor comes from: The mile is exactly 1.609344 kilometres, because it is 5,280 feet of exactly 0.3048 m. Factors on UnitPairs follow the NIST definitions, so results agree between pages to the last digit shown.
miles to kilometres chart
| miles (mi) | kilometres (km) |
|---|---|
| 1 | 1.609344 |
| 2 | 3.218688 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 20 | 32.18688 |
| 26.2 | 42.164813 |
| 50 | 80.4672 |
| 100 | 160.9344 |
Questions
How many kilometres are in one mile?
Exactly 1.609344 km — that is the rate this converter applies in both directions.
How do I convert mi to km by hand?
Multiply the miles value by 1.609344. For a rough mental estimate, 1.609 is usually close enough — but use the full factor for anything you plan to build, buy or dose.
How accurate is this converter?
The factors are the exact international definitions, so the only rounding is in the display — results are shown to six decimal places, and the underlying value is never pre-rounded.
Related conversions
- kilometres to miles — the reverse of this page
- centimetres to inches
- inches to centimetres
- metres to feet
- feet to metres
- kilometres to miles
- centimetres to feet
- Height converter — centimetres to feet and inches
- Full conversion chart — every pair on one page