Ans

Unit converter

Miles to kilometres.

Convert mi to km and km to mi. Type in either box and the other follows. A mile is exactly 1.609 344 km, so a marathon's 26.219 miles works out at 42.195 km.

mi → kmExact definition
—
Miles to kilometres — common values, to 6 significant figures.
mikm
1 mi1.60934 km
2 mi3.21869 km
3 mi4.82803 km
5 mi8.04672 km
10 mi16.0934 km
15 mi24.1402 km
20 mi32.1869 km
26.2188 mi42.1951 km
50 mi80.4672 km
100 mi160.934 km
1 mi=1.609344 km 1 km=0.6213711922 mi

Definitions

  • The statute mile is exactly 1609.344 m, or 5280 feet. It is the mile on UK and US road signs.
  • The kilometre is a thousand metres, and the unit road distances are signed in almost everywhere except the UK and the US.
  • This conversion is exact by definition. 1 mi = 1.609344 km.
  • The metre is SI; every imperial and US customary length here is defined exactly in terms of it by the 1959 international yard and pound agreement.

How it works

One direction multiplies and the other divides by the same number, so nothing is lost by going back and forth.

The value passes through m, the unit every other length & distance unit on the site is defined against, rather than a number written into this page on its own. That is why the figure here, the figure in the table above and the general length & distance converter always agree.

Display precision limits significant figures rather than decimal places, because one fixed number of decimals is useless across a range this wide. Very large and very small results switch to scientific notation with a proper superscript exponent. The editable box always holds a plain number at full working precision, so you can carry on from either side.

Common questions this answers: how many kilometres in a mile (1.60934), how many miles in a kilometre (0.621371), and what 26.2188 mi is in kilometres (42.1951 km).

From the maker of Ans — a scientific calculator you can own. Same idea: a proper instrument, nothing in the way.