Speed converter
Speed converter: km/h, mph, m/s, knots.
Free online speed converter
Convert speed between metres per second, kilometres per hour, miles per hour, knots and feet per second. Useful for driving, running, sailing and weather.
Common speed conversions
1 km/h = 0.621 mph, 1 mph = 1.609 km/h, 1 knot = 1.852 km/h, 1 m/s = 3.6 km/h.
FAQ
What is 100 km/h in mph? About 62.1 mph. What is a knot? One nautical mile per hour.
Knots in sailing and aviation
A knot (kn) is one nautical mile per hour and is the standard speed unit in sea and air navigation. 1 knot = 1.852 km/h = 0.514 m/s ≈ 1.151 mph.
Where does the word "knot" come from?
From the old chip log: a board tied to a rope with knots at regular intervals was thrown off the stern. While a sandglass ran, sailors counted how many knots passed through their hands; that number was the ship’s speed. So "so many knots" came to mean "so many nautical miles per hour".
What is a nautical mile?
A nautical mile equals one minute of arc of latitude along a meridian, fixed internationally at exactly 1,852 metres. It is handy for navigation: since one degree has 60 minutes, 1° of latitude = 60 nautical miles, tying distance directly to the coordinates on a chart. It differs from the land mile (1,609 m).