Convert miles per hour to kilometers per hour
Mile per hour (mph) to kilometer per hour (km/h). One mile per hour equals 1.6093 kilometers per hour.
Formula
Mile per hour to kilometer per hour conversion table
| Miles per hour | Kilometers per hour | Kilometers per hour | Miles per hour |
|---|---|---|---|
| 1 mph | 1.6093 km/h | 1 km/h | 0.621371 mph |
| 2 mph | 3.2187 km/h | 2 km/h | 1.2427 mph |
| 3 mph | 4.828 km/h | 3 km/h | 1.8641 mph |
| 5 mph | 8.0467 km/h | 5 km/h | 3.1069 mph |
| 10 mph | 16.0934 km/h | 10 km/h | 6.2137 mph |
| 20 mph | 32.1869 km/h | 20 km/h | 12.4274 mph |
| 50 mph | 80.4672 km/h | 50 km/h | 31.0686 mph |
| 100 mph | 160.93 km/h | 100 km/h | 62.1371 mph |
| 500 mph | 804.67 km/h | 500 km/h | 310.69 mph |
| 1000 mph | 1609.34 km/h | 1000 km/h | 621.37 mph |
To convert miles per hour to kilometers per hour, multiply the number of miles per hour by 1.6093. One mile per hour equals 1.6093 kilometers per hour, and one kilometer per hour equals 0.621371 miles per hour, so the relationship is fixed and exact. As a worked example, 10 mph comes to 16.0934 km/h. Enter your own figure in the converter above to get an instant answer, or use the swap button to flip the direction. This is a speed conversion, and like every tool on UnitGlide it runs locally in your browser with no account or upload required. The table further down shows a range of common mile per hour values already worked out in kilometers per hour, plus the reverse kilometer per hour to mile per hour direction, which is handy for quick reference or double-checking a result by hand.
Mile per hour to kilometer per hour in practice
Miles per hour to kilometres per hour is the conversion a visitor to Britain or America makes in reverse, turning an mph limit or an mph dial into the metric figure they actually think in.
Everyday uses
US interstates run at 65 or 70 mph, which is 105 or 113 km/h, and a UK motorway's 70 mph limit is 113 km/h too. People importing an American or British car often want the km/h equivalents for a speedometer overlay or a dashboard swap. Sports speeds cross over as well: a 95 mph baseball pitch is 153 km/h, and a 30 mph sprint finish is 48 km/h.
A quick mental method
One mph is exactly 1.609344 km/h. For a fast estimate, add 60 percent to the mph figure: 70 plus 60 percent of 70 is about 112, against an exact 112.7. That is sharper than the rough 'times 1.6', which understates a little and drifts further as the speed climbs toward highway pace.
Landmark speeds
A handful of anchors covers most cases: 30 mph is 48 km/h, 50 mph is 80 km/h, and 60 mph is 97 km/h, just shy of the round 100. Knowing that 62 mph is almost exactly 100 km/h lets you sanity-check any answer at a glance and spot a slipped decimal.
Convert the number, then reattach the hour
Because mph and km/h both carry the 'per hour', the maths is just a plain miles-to-kilometres step done on the speed. The only slip is trying to convert the whole compound label at once; convert the number, then put the 'per hour' back, and the result stays correct.
Reading a foreign dashboard
A driver used to km/h glancing at an mph-only dial can misjudge how fast they are going by more than half again, since 60 on the dial is nearly 100 in their head. That is why hire cars in the US unsettle metric drivers at first: the number looks slow while the car is at full motorway speed. Converting a few key limits before setting off settles the nerves.
Frequently asked questions
How many kilometers per hour are in a mile per hour?
One mile per hour equals 1.6093 kilometers per hour. The ratio is constant, so you can multiply any number of miles per hour by 1.6093 to get kilometers per hour.
What is the formula to convert miles per hour to kilometers per hour?
Use kilometers per hour = miles per hour × 1.6093. UnitGlide applies this exact formula for every value, so results stay accurate across the whole range.
How do I convert kilometers per hour back to miles per hour?
Go the other way by using one kilometer per hour equals 0.621371 miles per hour. You can also press the swap button in the converter above to flip the direction in one click.
Is this mile per hour to kilometer per hour converter accurate?
Yes. It uses internationally defined SI conversion factors, as maintained by the BIPM, and all math runs in your browser so nothing is rounded away on a server. For everyday use the displayed precision is more than enough.