Km/h to Mph Converter — Speed Limits, Wind and Knots

How to convert km/h to mph

Divide the speed in kilometers per hour by 1.609344:

miles per hour = kilometers per hour ÷ 1.609344

100 km/h ÷ 1.609344 = 62.137 mph, or 62.14 mph. The factor is exact, because a mile is defined as 1.609344 km. To go the other way, multiply mph by 1.609344 — type the mph into the second field. For distances rather than speeds, use km to miles.

Speed limit signs in mph

Canada, Mexico and most of the world post speed limits in km/h. Common signs and what they mean in mph:

Sign (km/h)	mph	Typical road
30	18.64	school zones, residential streets
40	24.85	residential and urban streets
50	31.07	towns and cities
60	37.28	urban arterials
70	43.5	rural and suburban roads
80	49.71	rural highways
90	55.92	rural highways
100	62.14	Canadian highways, expressways
110	68.35	some Canadian and European highways
120	74.56	motorways
130	80.78	European motorways

Rental cars abroad usually have a speedometer marked mainly in km/h. The limit on the sign is the law — round down rather than up when you convert in your head. On a dual-scale speedometer, the inner ring is usually the secondary unit; 100 on the outer km/h scale lines up with about 62 on the mph scale.

Wind speed, meters per second and knots

Weather services report wind in different units: km/h in Canada and Europe, mph in the U.S., meters per second in science and aviation weather, knots at sea. The result lists all of them:

36 km/h = 22.37 mph = 10 m/s = 19.44 knots;
60 km/h = 37.28 mph = 16.67 m/s = 32.4 knots;
120 km/h = 74.56 mph = 33.33 m/s = 64.79 knots.

Treadmills, running and cycling

Treadmills and bike computers can show either unit, and training plans from abroad give speeds in km/h:

km/h	mph	Time per km	Time per mile
6	3.73	10:00	16:06
8	4.97	7:30	12:04
10	6.21	6:00	9:39
12	7.46	5:00	8:03
15	9.32	4:00	6:26
25	15.53	2:24	3:52

To turn a speed into time per kilometer, divide 60 by the km/h: 10 km/h is 6 minutes per km. For distances in meters on a track, see meters to kilometers.

Quick ways to estimate

Method	80 km/h gives	Error
÷ 1.609344 (exact)	49.71 mph	—
× 5 ÷ 8	50 mph	+0.6%
× 0.6	48 mph	−3.4%

Multiply by 5, divide by 8 is the easiest accurate shortcut. For distances on the same trip, see miles to km.

Frequently asked questions

How fast is 100 km/h in mph?

62.14 mph. It is the usual highway limit in Canada and on many roads in Europe — a little below the 65 mph of many U.S. highways.

How do I convert km/h to mph?

Divide by 1.609344, the number of kilometers in a mile — or multiply by 0.621371. 80 km/h ÷ 1.609344 = 49.71 mph.

What is 120 km/h in mph?

74.56 mph. 130 km/h, a common motorway limit in Europe, is 80.78 mph.

Is 50 km/h about 30 mph?

Close: 50 km/h is 31.07 mph. Many towns abroad use 50 km/h where a U.S. town would post 30 mph.

How many km/h is 1 m/s?

3.6 km/h, which is 2.237 mph. Divide km/h by 3.6 to get meters per second.

How many mph is a knot?

1.1508 mph. A knot is one nautical mile (1,852 m) per hour, so it is also 1.852 km/h.