Speed Converter

Convert speed between km/h, mph, m/s, knots and ft/s instantly.

Reviewed by the WorldCalcs team · Methodology · Last reviewed: June 2026

Result

62.137119 mph

100 kmh = 62.137119 mph

All units

100 kmh converted into every supported unit.

UnitValue
Meters per second (m/s)27.777778
Kilometers per hour (km/h)100
Miles per hour (mph)62.137119
Knots (kn)53.99568
Feet per second (ft/s)91.134442

What is a speed converter?

A speed converter changes a rate of travel between units such as kilometres per hour (km/h), miles per hour (mph), metres per second (m/s) and knots. It is handy for driving, running, weather and sailing.

How it works

Each unit is a length divided by a time, so the tool converts using the underlying length and time ratios. For example 1 km/h means 1000 m in 3600 s. The defining values are exact: 1 mile = 1.609344 km, and 1 knot = 1 nautical mile per hour = 1.852 km/h.

All calculations happen in your browser. Nothing is sent, stored, or tracked.

Results are estimates and may contain errors — for general information only, not professional advice. Always verify before relying on them. Disclaimer

How to use

Type a value, then pick the unit you have it in and the unit you want it in. The result updates instantly.

All conversions go through meters per second using exact internationally defined factors.

Frequently asked questions

What is a knot?+

A knot is one nautical mile per hour — exactly 1852/3600 m/s, or about 1.852 km/h. It's used in aviation and at sea.

How do I convert km/h to mph?+

Multiply km/h by 0.621371 to get mph (or divide by 1.609344). The converter does this exactly for you.

Are the factors exact?+

Yes. 1 mph = 0.44704 m/s, 1 ft/s = 0.3048 m/s, 1 knot = 1852/3600 m/s, 1 km/h = 1/3.6 m/s — all internationally defined.

How many mph is 100 km/h?+

About 62.14 mph (1 km/h = 0.621371 mph).

How fast is a knot in km/h?+

Exactly 1.852 km/h.

How do I convert m/s to km/h?+

Multiply by 3.6 (1 m/s = 3.6 km/h).

What is 1 mph in m/s?+

Exactly 0.44704 m/s.