kilometers per hour to miles per hour Converter
Type a value in kilometers per hour and get the answer in miles per hour instantly — or convert the other way. The conversion uses the exact relationship 1 kilometers per hour = 0.621371 miles per hour, the same formula used in textbooks and engineering references.
Speed limits and car dashboards use km/h almost everywhere; the US and UK still speak in mph. One km/h is 0.6214 mph, so 100 km/h on a European motorway is a legal 62 mph — and 60 mph is a ticket-prone 96.6 km/h.
How to use
- Type your value into the kilometers per hour box — the miles per hour result updates as you type.
- To go the other direction, type into the miles per hour box instead and read the kilometers per hour result.
- Copy the result with one tap, or scan the reference table below for common values.
Frequently asked questions
How do you convert kilometers per hour to miles per hour?
Multiply the number of kilometers per hour by 0.621371. For example, 10 kilometers per hour = 6.21371 miles per hour. The converter above does this for you and shows more decimal places than you will ever need.
How many miles per hour are in one kilometers per hour?
Exactly 0.621371 miles per hour. This is a fixed definition, not an approximation, so the conversion is exact at any scale.
Is this converter accurate for professional use?
Yes — it uses full double-precision arithmetic and the official kilometers per hour-to-miles per hour factor, so results are reliable for schoolwork, cooking, fitness, travel and technical work.
Can I convert miles per hour back to kilometers per hour?
Yes. The converter is two-way: just type in the second box and the first box updates instantly with the reverse conversion.