Miles per Hour to Kilometers per Hour
Convert miles per hour to kilometers per hour instantly. 1 mph = 1.609344 km/h. Includes the exact factor, a conversion table of common values and the definition of both units.
How to convert miles per hour to kilometers per hour
To convert miles per hour to kilometers per hour, multiply by 1.609344. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.
km/h = mph × 1.609344
Miles per Hour to Kilometers per Hour conversion table
The values people look up most often, rounded for reading. Use the calculator above for anything in between.
| Miles per Hour | Kilometers per Hour |
|---|---|
| 1 mph | 1.609344 km/h |
| 2 mph | 3.218688 km/h |
| 3 mph | 4.828032 km/h |
| 5 mph | 8.04672 km/h |
| 10 mph | 16.09344 km/h |
| 20 mph | 32.18688 km/h |
| 25 mph | 40.2336 km/h |
| 50 mph | 80.4672 km/h |
| 100 mph | 160.9344 km/h |
| 500 mph | 804.672 km/h |
| 1,000 mph | 1,609.34 km/h |
What is a miles per hour?
Exactly 0.44704 m/s. Road speeds in the US and UK.
What is a kilometers per hour?
The road-speed unit almost everywhere outside the US and UK.
The formula
km/h = mph × 1.609344
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the Miles per Hour to Kilometers per Hour
- Type the number of miles per hour you want to convert.
- Read the result in kilometers per hour straight away — there is no button to press.
- Check the table below for the values that come up most often, or reverse the conversion with the linked kilometers per hour to miles per hour page.
Miles per Hour to Kilometers per Hour — frequently asked questions
How many kilometers per hour are in a miles per hour?
One miles per hour equals 1.609344 km/h. km/h = mph × 1.609344
What is the formula to convert miles per hour to kilometers per hour?
The formula is km/h = mph × 1.609344. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.
How do I convert kilometers per hour back to miles per hour?
Divide instead of multiplying: one kilometers per hour is 0.6213711922 mph. The reverse converter is linked in the related tools list.
Is this conversion exact?
Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.
Is this miles per hour to kilometers per hour free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the miles per hour to kilometers per hour.
- miles per hour to kilometers per hour
- 1 miles per hour to kilometers per hour
- how many kilometers per hour in a miles per hour
- mph2km/h
- miles per hour in kilometers per hour
- miles per hour to kilometers per hour converter
- convert miles per hour to kilometers per hour
About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error