Miles to Kilometers Converter

One mile is exactly 1.609344 kilometers:

kilometers = miles × 1.609344

The factor looks arbitrary because it is: a mile is 5,280 feet, and a foot is 0.3048 m, so the mile inherits a number nobody chose deliberately.

Running distances are the most common reason to convert:

Race	Miles	Kilometers
5K	3.107	5
10K	6.214	10
Half marathon	13.109	21.1
Marathon	26.219	42.195

Note the direction of the rounding. A 5K is defined as exactly 5 km, and 3.107 miles is the conversion of it — not the other way round. The marathon's 42.195 km comes from the 1908 London Olympic course, which is why it resists a tidy number in either system.

Two more contexts:

• Speed limits. A 70 mph motorway limit is 112.65 km/h, which most European countries round to 110 or 120. A 30 mph urban limit is 48.28 km/h, near the 50 km/h standard.
• Fuel and range. An electric car rated 300 miles has 482.8 km of range on the same test cycle — though EPA and WLTP cycles are not comparable, so a converted figure is not a like-for-like one.

The mental shortcut is add 60%: 10 miles → 16 km, against a true 16.09. For quick work it is accurate to well under a percent.