Ans

Unit converter

Kilometres to miles.

Convert km to mi and mi to km. Type in either box and the other follows. UK road signs are in miles while almost every other European country signs in kilometres — 1 km is about 0.621 miles.

km → miExact definition
—
Kilometres to miles — common values, to 6 significant figures.
kmmi
1 km0.621371 mi
2 km1.24274 mi
3 km1.86411 mi
5 km3.10686 mi
10 km6.21371 mi
15 km9.32057 mi
20 km12.4274 mi
25 km15.5343 mi
50 km31.0686 mi
100 km62.1371 mi
200 km124.274 mi
1 km=0.6213711922 mi 1 mi=1.609344 km

Definitions

  • The kilometre is a thousand metres, and the unit road distances are signed in almost everywhere except the UK and the US.
  • The statute mile is exactly 1609.344 m, or 5280 feet. It is the mile on UK and US road signs.
  • This conversion is exact by definition. 1 km = 0.6213711922 mi.
  • 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 miles in a kilometre (0.621371), how many kilometres in a mile (1.60934), and what 100 km is in miles (62.1371 mi).

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