Unit converter
Speed converter
Instant conversion in your browser — speed.
1 km/h = 0.6213711923 mph
Quick table Kilometers per hour → Miles per hour
| km/h | mph |
|---|---|
| 1 | 0.6213711923 |
| 5 | 3.106855961 |
| 10 | 6.213711923 |
| 25 | 15.53427981 |
| 50 | 31.06855961 |
| 100 | 62.13711923 |
| 500 | 310.6855961 |
| 1,000 | 621.3711923 |
1 kilometers per hour (km/h) in every unit
| Miles per hour | 0.6213711923 mph |
| Meters per second | 0.2777777778 m/s |
| Knots | 0.5399568035 kn |
About speed units
Four units, four different worlds. Kilometres per hour on European roads, miles per hour in the US and UK, metres per second in physics and weather bulletins, knots at sea and in the air.
The knot is the interesting one: it is one nautical mile per hour, and a nautical mile is one minute of latitude. That is why sailors can measure distance on a chart with dividers against the latitude scale in the margin — no conversion needed. "Knots per hour" is wrong; a knot is already a speed.
The one rule worth memorising: metres per second × 3.6 = kilometres per hour.
About this conversion
Speed conversion: 1 kilometers per hour (km/h) equals 0.6213711923 mph. As a practical reference, 2 km/h = 1.242742385 mph — relevant for driving, running pace and wind forecasts.
| km/h | mph |
|---|---|
| 2 | 1.242742385 |
Frequently asked questions
Why is wind speed given in metres per second?
Because it is the SI unit, and many national weather services publish in it. To read it as road speed, multiply by 3.6: a 10 m/s wind is 36 km/h.
What speed limits will I meet abroad?
Typical European limits are 50 km/h in town (31 mph), 90 km/h on main roads (56 mph) and 130 km/h on motorways (81 mph). British motorways are 70 mph (113 km/h), US interstates commonly 65–75 mph (105–121 km/h).
How fast is a boat in knots, really?
A cruising sailboat does 5–8 knots (9–15 km/h), a motorboat 25–30 knots (46–56 km/h), an airliner cruises around 450–500 knots (830–930 km/h).
Can I estimate mph from km/h in my head?
Take away a third and you are within a couple of per cent: 100 km/h minus a third is about 66, the true value is 62 mph. Good enough to read a road sign, not to argue with a speed camera.