Speed Converter
Speed is a distance over a time, so converting it means handling both at once. The everyday pair is mph and km/h (multiply mph by 1.609), but m/s shows up in science and weather, and knots in aviation and sailing. The one shortcut worth memorising: m/s × 3.6 = km/h.
Speeds in context
| Speed | Equivalents | What it is |
|---|---|---|
| 5 km/h | 3.1 mph, 1.4 m/s | a brisk walk |
| 30 mph | 48 km/h, 13.4 m/s | an urban limit |
| 60 mph | 96.6 km/h, 26.8 m/s | a US highway |
| 100 km/h | 62 mph, 27.8 m/s | a motorway limit |
| 10 knots | 18.5 km/h, 11.5 mph | a light sailing breeze |
Running pace is the inverse
Runners quote pace as time per distance (minutes per km or per mile), which is 1/speed. A 5:00 min/km pace is 12 km/h; a 6:26 min/mile pace is the same speed. To convert a race distance rather than a speed, use miles to km. To work out how long a trip takes at a given speed, the time converter helps with the units.
Knots and why they exist
A knot is one nautical mile per hour, and a nautical mile (1,852 m) is one minute of latitude – which makes navigation by chart straightforward. That is why ships and aircraft use knots while everyone else uses mph or km/h. 1 knot is 1.852 km/h or 1.151 mph.
FAQ
How do I convert mph to km/h?
Multiply mph by 1.60934. So 70 mph is about 112.7 km/h. For a quick estimate, multiply by 1.6.
How do I convert m/s to km/h?
Multiply by 3.6. For example, 25 m/s = 90 km/h.
What is a knot?
One nautical mile per hour: 1.852 km/h, or 1.151 mph. Used in aviation and at sea.
How fast is 100 km/h in mph?
About 62 mph.
Is km/h the same as kph?
Yes - "kph" and "km/h" both mean kilometres per hour. "km/h" is the standard written form.