Speed Converter

Convert km/h, mph, m/s, knots and Mach.

Value

Decimal places

From

1 km/h in mile per hour

0.621371 mph

1 km/h = 0.62137119 mph

1 km/h expressed in every speed & velocity unit.
Unit	Symbol	Value
Metre per second	m/s	0.277778
Kilometre per hour	km/h	1
Mile per hour	mph	0.621371
Foot per second	ft/s	0.911344
Knot	kn	0.539957
Mach (sea level, 20 °C)	Ma	0.000810
Speed of light	c	0

What does Speed Converter do?

Convert between seven speed units including knots for marine and air navigation and Mach for aviation. Pace conversion is included for runners, turning speed into minutes per kilometre or mile.

How to Use Speed Converter

1
Enter a speedAny value.
2
Choose the unitsFrom and to.
3
Read the resultPlus pace for runners.

Key Features

Seven units including knots, Mach and the speed of light
Running pace in minutes per kilometre and per mile
Common speed limits shown for reference
Exact factor: 1 mph = 0.44704 m/s
Mach clearly labelled as sea level at 20 °C, since it varies with conditions

Frequently Asked Questions

How do I convert km/h to mph?

Divide by 1.609344. 100 km/h is 62.14 mph. For a rough estimate, multiply by 0.6 — close enough to read a speedometer.

What is a knot?

One nautical mile per hour, which is 1.852 km/h or 1.151 mph. It is used at sea and in aviation because a nautical mile is one minute of latitude, which makes chart navigation straightforward.

Is Mach a fixed speed?

No. Mach 1 is the local speed of sound, which depends on air temperature. At sea level and 20 °C it is about 343 m/s, but at cruising altitude it drops to roughly 295 m/s. The listed value states its conditions.

How does pace relate to speed?

Pace is the inverse — minutes per unit distance rather than distance per hour. Running 12 km/h is a 5:00 min/km pace. Runners use pace because it maps directly onto a target finish time.