How to convert miles and kilometres
One mile is exactly 1.609344 kilometres. To go from miles to kilometres you multiply by 1.609344; to go the other way you divide by it (or multiply by 0.621371).
A quick mental shortcut: kilometres are a little over one and a half times the number of miles. So 60 mph is roughly 97 km/h, and a 10 km run is about 6.2 miles.
The mile is still used for road distances and speed limits in the UK and the US, while almost every other country uses kilometres, which is why this conversion comes up so often when driving abroad or reading running and cycling distances.