Speed Converter (km/h to mph)

Enter a speed and pick units — the conversion updates instantly.

Your text and files never leave your browser — nothing is sent to a server.

ValueFromTo

Show all units

How to use

Type a speed in “Value” and choose the units to convert from and to.
The arrow button in the middle flips km/h → mph into mph → km/h.
“Show all units” lists the same speed in m/s, knots, Mach and every other unit at once.
The page address keeps your value and units, so you can share the link as is.

How fast is 100 km/h in mph?

About 62.1 mph. One mph is exactly 1.609344 km/h, so multiply mph by 1.609 to get km/h.

How do I turn m/s into km/h?

Multiply by 3.6. A wind of 30 m/s, for example, is 108 km/h or about 67 mph.

What is a knot?

One nautical mile (1,852 m) per hour, which is 1.852 km/h. Ships, aircraft and marine weather reports use it.

How fast is Mach 1?

The speed of sound changes with temperature. This tool uses 340.29 m/s, the standard sea-level value at 15 °C — about 1,225 km/h or 761 mph.