Convert kilometres to miles

Formula: mi = km × 0.621371

km to mi quick reference table

Everyday km values, converted

• 5 km = 3.1069 mi — a 5K run.
• 10 km = 6.2137 mi — a 10K run.
• 42.195 km = 26.2188 mi — a marathon.

Where km to mi comes up

Length conversions come up in DIY and construction, screen and print sizing, running distances, and clothing or furniture measurements ordered from abroad. Mixed-unit plans are the usual reason a cut ends up wrong.

Doing km to mi in your head

Multiply by 6 and drop a digit, or use the 5:8 rule — 5 miles is about 8 kilometres. 100 km becomes roughly 62 miles.

Precision and rounding

One kilometre is exactly 0.621371 miles under the current definitions of both units, so the only judgement call is how many digits you keep. Two decimal places is already finer than most household scales and tape measures can read, while engineering and medical work usually keeps the full factor and rounds once at the end rather than at every step.