kilometres to miles converter
1 km = 0.6213711922 mi. Type a value in either box — the other side updates instantly, using the exact definition factor, not a rounded shortcut. Road distances and running races: a marathon is 42.195 km — this pair turns it into the familiar 26.2 miles.
Rate: 1 km = 0.6213711922 mi · 1 mi = 1.609344 km
Formula and a worked example
miles = kilometres × 0.6213711922. Worked example: 42.195 km × 0.6213711922 = 26.218757 mi. To go back, divide by the same factor (or multiply by 1.609344).
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.
kilometres to miles chart
| kilometres (km) | miles (mi) |
|---|---|
| 1 | 0.621371 |
| 2 | 1.242742 |
| 5 | 3.106856 |
| 10 | 6.213712 |
| 20 | 12.427424 |
| 42.195 | 26.218757 |
| 50 | 31.06856 |
| 100 | 62.137119 |
Questions
How many miles are in one kilometre?
Exactly 0.6213711922 mi — that is the rate this converter applies in both directions.
How do I convert km to mi by hand?
Multiply the kilometres value by 0.6213711922. For a rough mental estimate, 0.621 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
- miles to kilometres — the reverse of this page
- centimetres to inches
- inches to centimetres
- metres to feet
- feet to metres
- miles to kilometres
- centimetres to feet
- Height converter — centimetres to feet and inches
- Full conversion chart — every pair on one page