🚀 Speed Converter

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

About this tool

Converts between five speed units — mph, km/h, m/s, knots, and feet per second — through a shared meters-per-second base.

Covers knots, the unit used in marine and aviation contexts, alongside everyday road-speed units.

Worked example

A cruising airliner at 500 knots is about 926 km/h, and a 10 m/s wind is about 22.4 mph.

How to use it

Enter a value.
Choose the unit you're converting from.
Choose the unit you want, and press Convert.

Tips

1 knot equals 1 nautical mile per hour — used for ships, aircraft, and wind speed, not road vehicles.
For a fast, dedicated mph↔km/h conversion, our pair page skips the dropdown entirely.
m/s is the standard scientific unit used in physics problems and weather data.

FAQ

What is a knot in mph?

1 knot is about 1.15 mph.

Why do sailors and pilots use knots instead of mph?

Knots are directly tied to nautical miles, which align with lines of longitude on navigation charts, making distance and speed calculations more convenient at sea and in the air.

How many m/s is highway speed?

A 65 mph highway speed is about 29 m/s.

From the blog: getting the most out of this tool

Knots are the outlier unit here that trips people up — sailors, pilots, and meteorologists use it constantly, but it rarely shows up in everyday conversation, so we made sure it's included rather than treating this as just an mph/km/h swap.

For the single most common pair — mph to km/h for driving abroad — our dedicated converter page is quicker to use than this full dropdown version.