KM/H to MPH
Convert km/h to mph — 100 km/h is 62 mph. Road-speed table for driving abroad.
Fast, easy and free — your answer appears as you type, and whatever you enter stays on your device.
One kilometre per hour is 0.6214 miles per hour — 100 km/h is 62 mph. Type any speed below for the exact figure, or read the road-speed table before driving somewhere that signs the other unit.
How to use it
- Type the kilometres per hour valueThe miles per hour answer appears as you type — no button to press.
- Or go the other waySwap flips the direction to miles per hour → kilometres per hour in one tap.
- Check the workingThe exact factor or formula used is shown beneath the answer, so the result is checkable, not just asserted.
Road speeds: km/h in mph
| km/h | mph |
|---|---|
| 30 km/h | 18.64 mph |
| 50 km/h | 31.07 mph |
| 60 km/h | 37.28 mph |
| 80 km/h | 49.71 mph |
| 100 km/h | 62.14 mph |
| 110 km/h | 68.35 mph |
| 120 km/h | 74.56 mph |
| 130 km/h | 80.78 mph |
The quick rule for your head
Multiply by 0.6 for the safe estimate: 120 km/h × 0.6 = 72 mph (exact: 74.6). The estimate reads slightly low, which errs on the right side of a speed limit. The pairs worth memorising outright: 50 km/h ≈ 31 mph (towns), 100 ≈ 62, 130 ≈ 81 (motorways).
Where this conversion shows up
Driving is nearly the whole story: rental cars whose dashboards major in the wrong unit, UK drivers crossing to the continent and back, and speed-limit intuition that fails abroad in both directions. Cycling computers and treadmills contribute the rest, arriving configured for whichever market they were bought in.
Need other units too? The fullspeed converter handles every pair and shows the exact factor behind each answer.
Questions people ask
What is 100 km/h in mph?
62.1 mph. It is the metric world's default highway speed and converts to a number that sounds oddly specific in mph — which is why the table exists.
What is 30 mph in km/h?
48.3 km/h — the UK town limit is effectively the metric 50. The two systems' urban limits are near-twins: 30/50, and the school-zone 20 mph is 32 km/h.
Is the conversion exact?
Yes — the mile is exactly 1.609344 km, so mph and km/h convert by exact definition, rounded only for display.
My car shows both — which ring is which?
The larger, outer scale matches the country the car was sold for. GPS apps follow the phone's region settings rather than the road you are on, which is exactly when a converter earns its keep.