Miles to km

The exact conversion

Miles to kilometers turns a US road sign, a training plan, or a car’s range into the unit used on most of the rest of the world’s maps. The statute mile is exactly 1.609344 kilometers. One mile is a bit more than one and a half kilometers. Ten miles is 16.09 kilometers. One hundred miles is 160.93 kilometers. Multiplying by 1.6 is a good check; multiplying by 8/5 is the same shortcut, since 8/5 = 1.6.

The formula used above is km = mi × 1.609344. Both boxes stay in step, so you can start from either unit. Results are rounded for display; the factor itself is the legal definition, not a rounded shortcut.

Worked examples

Each line is the same formula with a new starting number. You can match it against the converter by typing the value on the left.

• 1 mile: 1 × 1.609344 = 1.6093 kilometers.
• 26.2 miles: 26.2 × 1.609344 = 42.1648 kilometers.
• 100 miles: 100 × 1.609344 = 160.9344 kilometers.

Where the rounding matters

Race distances are often remembered in miles even when the course was measured in meters. The figure 26.2 miles is 42.16 kilometers, a hair under the official marathon of 42.195 km (which is 26.219 miles). A 5-mile park loop is 8.05 kilometers. A 60-mile drive is 96.56 kilometers. None of these use the nautical mile. If a chart says nmi or NM, do not use this factor.

The kilometer result should be larger than the mile result. A result that shrank means the division was used instead of the multiplication. You can audit a number by sending it through km to miles: 16.09 km comes back as 10 miles, aside from rounding at the second decimal.

Conversion table: miles to km