Kilometers to Miles (km to mi)

Formula: mi = km ÷ 1.609344

km to miles chart

Related: miles to km · mph to km/h · cm to inches · Celsius to Fahrenheit

Kilometres to Miles at a glance

Kilometres are the standard road unit in most countries; the 21.1 and 42.2 rows are the half and full marathon distances.

Both directions from one number

You only need to remember one factor, because the reverse is its reciprocal:

mi = km × 0.621371
km = mi × 1.6093   (or divide by 0.621371)

If a result looks about right but is off by a large multiple, you have almost certainly multiplied where you should have divided — checking the direction against the table above catches it immediately.

Rounding, and how precise to be

Converting does not create accuracy that was not in the original measurement. If someone tells you a distance in whole kilometres, the converted figure is only as good as that starting estimate — quoting it to four decimal places implies a precision nobody measured.

A practical rule: keep roughly the same number of significant figures you started with, and round only at the end. Rounding at each intermediate step compounds the error, which is how a chain of conversions drifts away from the right answer.

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