How do I convert mph to km/h?

Multiply miles per hour (mph) by 1.609344 to get kilometers per hour (km/h). For example 50 mph × 1.609344 = 80.47 km/h.

A knot is a unit of speed equal to one nautical mile per hour, commonly used in aviation and maritime contexts. 1 knot = 1.852 km/h.

Can I convert m/s to mph?

Yes. First convert m/s to km/h by multiplying by 3.6, then to mph by dividing by 1.609344. This tool does it automatically.

Speed Converter – mph, km/h, m/s, knots, ft/s

Speed Converter (mph, km/h, m/s, knots)

Convert between the most common speed units instantly. Type a value in any field to see all the other units update automatically.

Kilometers per hour km/h (kph)

Miles per hour mph

Meters per second m/s

Knots kt

Feet per second ft/s

Common conversions

From	To	Multiply by
mph	km/h	1.609344
km/h	mph	0.621371
m/s	km/h	3.6
km/h	m/s	0.277778
knots	km/h	1.852
km/h	knots	0.539957

How the speed converter works

We use meters per second (m/s) as an internal reference. Every time you type a value, we convert it to m/s, then from m/s to all the other units. This keeps all fields synchronized.

Base relations

1 km/h = 0.2777777778 m/s
1 mph = 1.609344 km/h
1 knot = 1.852 km/h
1 ft/s = 0.3048 m/s

FAQ

Why do my numbers have many decimals? We keep precision to avoid rounding errors. Round to the number of decimals you need.
Is speed the same as velocity? In physics, velocity has direction. This tool converts scalar speed.