Converters
Speed Converter
Convert speed between km/h, mph, knots and more.
About the Speed Converter
The Speed Converter switches between metres per second, kilometres per hour, miles per hour, feet per second and knots, the units used for driving, science, sport and navigation.
What you can do with the Speed Converter
- Converts both ways: Type in either box and the other one updates as you type.
- Every unit at once: The "In every unit" list shows your value in m/s, km/h, mph, knots and ft/s. Tap one to switch to it.
- One-tap swap: The ⇅ button flips the two units, and the line under the boxes shows the rate for 1 unit.
- Road, sea and science: Switch between road speeds, nautical knots and the m/s used in physics.
The easy m/s to km/h rule
There are 3,600 seconds in an hour and 1,000 metres in a kilometre, so to turn metres per second into kilometres per hour you multiply by 3.6. A sprinter running at 10 m/s is moving at 36 km/h.
Knots at sea and in the air
A knot is one nautical mile per hour, which is exactly 1.852 km/h or about 1.15 mph. Ships, aircraft and weather reports for wind speed at sea use knots because nautical miles line up with latitude on navigation charts.
Everyday reference points
A typical walking pace is around 5 km/h (about 3 mph). A city speed limit of 50 km/h is about 31 mph, and motorway speeds of 100 km/h are about 62 mph. The speed of sound in air at room temperature is about 343 m/s, or roughly 1,235 km/h.
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Frequently Asked Questions
How do I convert km/h to mph?
Multiply by about 0.621. For example, 80 km/h is roughly 50 mph.
How fast is one knot?
1.852 km/h, which is about 1.15 mph.
Is m/s the same as meters per second in physics problems?
Yes, m/s is the standard SI unit for speed, so convert to it before using speed in physics formulas.
How many mph is 100 km/h?
100 km/h is about 62.14 mph, since one mile is exactly 1.609344 km. A quick estimate is to multiply km/h by 0.62. Going the other way, 60 mph is about 96.56 km/h. Pick km/h and mph to convert any speed.
How do I convert m/s to km/h?
Multiply metres per second by 3.6 to get km/h, and divide km/h by 3.6 to get m/s. So 10 m/s is 36 km/h and 72 km/h is 20 m/s. This rule comes from 3,600 seconds in an hour and 1,000 metres in a kilometre.
How fast is a 150 km/h cricket delivery in mph?
A 150 km/h delivery is about 93.2 mph, or about 41.7 m/s. Bowling speeds on Indian broadcasts are shown in km/h, while some overseas coverage uses mph. Type 150 with km/h selected and the "In every unit" list shows mph, m/s and ft/s.
What is the speed of sound in km/h?
In dry air at about 20 °C, sound travels at about 343 m/s, which is about 1,235 km/h or 767 mph. The exact figure changes with temperature. Type 343 with m/s selected to see it in every unit at once.
Can I convert running pace like minutes per km?
Pace is not one of the units here. To turn pace into speed, divide 60 by the minutes per km: 6 min/km is 10 km/h and 5 min/km is 12 km/h. Then type the km/h here to see mph or m/s.
How many km/h is one knot?
One knot is one nautical mile per hour, which is exactly 1.852 km/h or about 1.15 mph. Ships and aircraft use knots, and wind speeds in marine forecasts are often given in knots too. Pick knot and km/h to convert.
What is a feet per second speed used for?
Feet per second appears in US engineering, ballistics and some sports data. One ft/s is exactly 0.3048 m/s, or about 1.097 km/h. Pick ft/s in either box, or read it straight from the "In every unit" list after typing any speed.
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