Km/h to mph converter
Type a speed in kilometres per hour and see at once how many miles per hour (mph) that is. Converting from mph to km/h works too. Handy when you drive in the US or the UK.
In kilometres per hour or in miles per hour (mph).
Fill in the fields; the answer appears here straight away.
How it's worked out
How it works
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Enter the values
Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.
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Instant answer
The answer appears as you type, with the most important intermediate values.
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See the working
Under "How it's worked out" you see the steps, handy for checking your own calculation.
The formula
One mile is 1.609344 km, so:
- km/h to mph: divide by 1.609344 (or multiply by 0.621371)
- mph to km/h: multiply by 1.609344
120 km/h is 120 รท 1.609344 = 74.6 mph.
Conversion table
| km/h | mph |
|---|---|
| 10 km/h | 6.2 mph |
| 30 km/h | 18.6 mph |
| 50 km/h | 31.1 mph |
| 70 km/h | 43.5 mph |
| 80 km/h | 49.7 mph |
| 100 km/h | 62.1 mph |
| 120 km/h | 74.6 mph |
| 130 km/h | 80.8 mph |
| 150 km/h | 93.2 mph |
| 200 km/h | 124.3 mph |
A rule of thumb
Multiply km/h by 0.6 to get mph: 100 km/h is about 60 mph (exactly 62.1). A speed limit of 65 mph is about 105 km/h.
Speed limits to know
| Limit | mph | km/h |
|---|---|---|
| UK built-up area | 30 | 48.3 |
| UK single carriageway | 60 | 96.6 |
| UK motorway | 70 | 112.7 |
| US interstate (typical) | 65 | 104.6 |
| US residential street | 25 | 40.2 |
Wind and boats
Wind speeds are in knots at sea and km/h on land. A gale of force 8 is 34 to 40 knots, or 63 to 74 km/h. To convert km/h to mph for a weather report, use the factor above. A temperature in the same forecast is in Celsius to Fahrenheit.
Pace and speed
A speed of 12 km/h is 7.5 mph, a typical jogging speed. For distances on the same journey, see the km to miles converter.
Frequently asked questions
How do I convert km/h to metres per second?
Divide by 3.6. 120 km/h is 33.3 m/s, and 10 m/s is 36 km/h.
What are common speed limits in mph and km/h?
US interstates range from 55 to 80 mph, which is 88.5 to 128.7 km/h. The UK has 30 mph in towns (48.3 km/h), 60 mph on single roads (96.6 km/h) and 70 mph on motorways (112.7 km/h).
How much is a knot in km/h and mph?
One knot is 1.852 km/h, which is 1.151 mph. A 20-knot wind is 37 km/h or 23 mph.
Does my UK rental car show mph?
Yes. Cars in the UK and the US have a speedometer in mph, and many also show km/h in smaller numbers. Always check which unit the sign uses.