The kilometer (metric) and the mile (US/UK customary) both have exact definitions, making this a precise distance conversion.
How it works
Dividing kilometers by 1.609344 gives miles; multiplying miles by that same constant gives kilometers back. Type into either field and the other updates instantly.
What this does not include
This does not include the nautical mile, a different, longer unit (about 1.852 km) used in aviation and maritime navigation — this calculator uses the standard statute mile.
How to use this calculator
- Enter a value in either kilometers or miles — the other field fills in automatically.
Frequently asked questions
Why is 1 mile exactly 1.609344 km?
It’s the exact international definition set by a 1959 agreement, standardizing the mile as precisely 1,609.344 meters.
Where is this conversion most commonly needed?
Road distances and speed limits (most countries use km, the US and UK use miles), running/race distances, and reading vehicle specifications from a different country.
Is this the same as the nautical mile used at sea?
No — a nautical mile (about 1.852 km) is a different, longer unit based on a minute of latitude, distinct from the statute mile used on land.
