How to use

The speed converter changes values between km/h, mph, m/s, knots and ft/s. It converts through meters per second internally and also shows the most common units together, making quick comparisons easier for driving, sport, physics, navigation and aviation.

Enter the speed value.
Choose the source unit and the unit you want to convert to.
Calculate to see the selected conversion plus km/h, mph, m/s and knots together.

How it is calculated

Convert through m/s; 1 km/h = 0.277777… m/s, 1 mph = 0.44704 m/s, 1 knot = 0.514444… m/s

Example

Example: 100 km/h is about 27.7778 m/s, 62.1371 mph and 53.9957 knots. The conversions use the fixed international mile and nautical mile definitions.

Important notes

A knot is one nautical mile per hour, and the nautical mile is exactly 1,852 meters. mph uses the international mile of exactly 1,609.344 meters. These are unit conversions only; they do not determine legal speed limits, safe driving conditions or certified navigation data.

Frequently asked questions

How many mph is 100 km/h?

About 62.1371 mph.

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

Multiply meters per second by 3.6. So 10 m/s equals exactly 36 km/h.

What is the difference between a knot and mph?

A knot is one nautical mile per hour, equal to 1.852 km/h. mph is one international statute mile per hour, equal to 1.609344 km/h.

Is this calculator free?

Yes. It is free to use and requires no account.

Speed Converter