1 km/h = 0.621371 mph. To convert kilometres per hour to miles per hour, multiply by 0.621371. The reverse is: 1 mph = 1.60934 km/h.
Common Speed Conversions
30 km/h = 18.6 mph — urban speed limit in many countries
50 km/h = 31.1 mph
80 km/h = 49.7 mph
100 km/h = 62.1 mph — motorway cruise speed in km/h countries
120 km/h = 74.6 mph
UK and US Driving
The UK and US use mph for road speeds. Most of Europe and the rest of the world uses km/h. Hire car speedometers often show both, but this converter is handy for route planning.
Common Use Cases
Reading speed limit signs when driving in a different country
Converting car speedometer readings between units
Comparing vehicle top speeds across different formats