Speed Converter

Convert speed between meters per second, kilometers per hour, miles per hour, knots, feet per second, and Mach.

Convert instantly

Enter a value and choose the units. Your answer updates as you type.

Value

From

Result

3.6 Kilometer per hour (km/h)

Quick reference

Meter per second (m/s)1 base units
Kilometer per hour (km/h)0.2777777777777778 base units
Mile per hour (mph)0.44704 base units
Knot (kn)0.5144444444444445 base units
Foot per second (ft/s)0.3048 base units
Mach (at sea level)340.29 base units

About the Speed Converter

Speed relates distance to elapsed time, so it is used in road signs, aviation, maritime navigation, athletics, and physics. This converter uses meters per second as its base, with one international mile exactly 1,609.344 meters and one knot exactly one nautical mile per hour.

Mach is shown as an approximate sea-level speed of sound because the speed of sound changes with temperature, altitude, and air composition; for example, 60 mph is about 96.56064 km/h. For the distance component use the Length Converter, and for elapsed durations use the Time Converter.

Frequently asked questions

How many km/h are in 1 mph?

One mile per hour equals exactly 1.609344 kilometers per hour.

What is a knot?

One knot is one nautical mile per hour, or exactly 1,852 meters per hour (about 0.514444 m/s).

Is Mach a fixed speed?

No. Mach 1 depends on local conditions; this page uses an approximate 340.29 m/s reference at sea level.

Take this calculation further

Browse the converters calculators collection for more tools in this subject.

For a related calculation, use Time Converter to convert durations between seconds, minutes, hours, days, weeks, months, and years with clear fixed-duration assumptions. Alternatively, use Flow Converter to convert volumetric flow rate between cubic meters per second, liters per minute, gallons per minute, CFM, and more.

For the underlying method, read Length Conversion Without Guesswork: Metric, Imperial, and Precision.