How to convert min/km to min/mile

Multiply your pace in minutes per kilometre by 1.609344. A 5:00/km pace becomes 8.047 minutes per mile, which reads as 8:03. That single multiplication is the whole conversion, and everything below is about doing it without a calculator in your hand at kilometre 30.

The min/km to min/mile formula

A mile is 1.609344 kilometres exactly, fixed by the international yard and pound agreement of 1959. Because a mile is longer, it takes longer to cover, so your per-mile number is always the bigger one. Runners new to the conversion sometimes expect the opposite and assume they have made an arithmetic mistake.

Work in decimal minutes rather than minutes and seconds. Convert 5:30/km to 5.5, multiply by 1.609344 to get 8.851, then turn the 0.851 back into seconds by multiplying by 60. That gives 51 seconds, so 5:30/km is 8:51/mi.

Why the 1.6 shortcut costs you a place

Rounding the mile to 1.6 introduces a 0.6% error. Over a single kilometre nobody notices. Over a marathon at three hours it is about 16 seconds, which is enough to miss a Boston qualifying time you were otherwise inside.

The error also compounds in the wrong direction for the runners most likely to use the shortcut, because a slower pace means more minutes for the percentage to act on.

min/km to min/mile conversion chart

Paces from 3:00 to 8:00 per kilometre, in fifteen second steps.

Pace per km	Pace per mile
3:00 /km	4:50 /mi
3:15 /km	5:14 /mi
3:30 /km	5:38 /mi
3:45 /km	6:02 /mi
4:00 /km	6:26 /mi
4:15 /km	6:50 /mi
4:30 /km	7:15 /mi
4:45 /km	7:39 /mi
5:00 /km	8:03 /mi
5:15 /km	8:27 /mi
5:30 /km	8:51 /mi
5:45 /km	9:15 /mi
6:00 /km	9:39 /mi
6:15 /km	10:04 /mi
6:30 /km	10:28 /mi
6:45 /km	10:52 /mi
7:00 /km	11:16 /mi
7:15 /km	11:40 /mi
7:30 /km	12:04 /mi
7:45 /km	12:28 /mi
8:00 /km	12:52 /mi

Converting without doing the arithmetic

Milemark keeps both numbers on screen at once. Set the minute and second scrubber to your pace and the converted value updates underneath as you move, so you can feel where 5:15 lands against 5:20 rather than computing them one at a time.