Speed Converter

How the Speed Converter Works

A speed converter changes a rate of motion from one unit into another using fixed conversion factors. Speed is distance divided by time, so every unit combines a length unit with a time unit. The metre per second (m/s) is the SI unit, and the tool converts your value to m/s internally before producing the unit you select.

The most-used relationships are simple. 1 m/s = 3.6 km/h exactly, because there are 3,600 seconds in an hour and 1,000 metres in a kilometre (3600 / 1000 = 3.6). To convert km/h to m/s you divide by 3.6. The link between metric and imperial speed comes from the mile: 1 mph = 1.609344 km/h, since one mile equals 1.609344 km.

Knots, used in aviation and shipping, are based on the nautical mile: 1 knot = 1.852 km/h. The foot per second connects through 1 ft/s = 0.3048 m/s. To convert manually, multiply by the relevant factor; to reverse it, divide.

Common Speed Conversion Factors

This table lists the speed conversions people search for most, covering driving, running, sailing and physics.

From	To	Multiply by
1 m/s	km/h	3.6
1 mph	km/h	1.609344
1 km/h	mph	0.621371
1 knot	km/h	1.852
1 knot	mph	1.15078
1 m/s	mph	2.23694
1 ft/s	m/s	0.3048

For example, to convert 100 km/h to mph, multiply 100 by 0.621371 to get about 62.14 mph. To convert 10 m/s to km/h, multiply 10 by 3.6 to get 36 km/h.

Where Speed Conversions Are Used

Different fields and countries favour different speed units, so conversion is a constant need:

• Driving uses km/h in most of the world and mph in the US and UK, so 60 mph is about 96.6 km/h.
• Aviation and sailing measure speed in knots (nautical miles per hour).
• Physics and engineering default to metres per second for calculations.
• Running and cycling apps often switch between km/h, mph and pace per kilometre or mile.
• Weather reports give wind speed in km/h, mph or knots depending on the region.

A handy shortcut: to roughly convert km/h to mph in your head, multiply by 0.6; to go from mph to km/h, multiply by 1.6. For exact results, rely on the precise factors above, since the mile, nautical mile and metre are all defined exactly.

Tips for Accurate Speed Conversion

The calculator gives instant results, but understanding the structure of speed units helps you check answers and estimate quickly when travelling or studying physics.

• Remember the 3.6 rule. The single most useful fact is that 1 m/s equals 3.6 km/h. Multiply m/s by 3.6 to get km/h, and divide km/h by 3.6 to get m/s. This covers most physics homework.
• Do not mix knots with mph. Knots are nautical miles per hour, and a nautical mile (1.852 km) is longer than a statute mile (1.609 km). One knot is about 1.15 mph, not equal to it.
• Round at the final step. Carry full precision through the calculation; for example 60 mph is exactly 96.56064 km/h, which you would usually present as 96.6 km/h.
• Pace versus speed. Runners often use pace (minutes per kilometre or mile) rather than speed. Pace is the inverse of speed, so converting requires dividing into a fixed distance rather than a simple multiplication.

For mental estimates, multiply km/h by 0.6 to approximate mph, or mph by 1.6 for km/h. A speed of 100 km/h is about 62 mph, a brisk walk is around 5 km/h, and a typical highway limit of 70 mph is roughly 113 km/h. These shortcuts are perfect for reading foreign road signs, while the precise factors above give the accuracy needed for navigation, engineering and science. Bookmark this speed converter so the right formula is always within reach.