Convert between kilometres per hour, miles per hour, knots and metres per second. Free and exact.
The converter holds every speed as meters per second. That is the base unit of the measurement. A conversion takes two steps. The value you type is multiplied by the factor of the unit it is written in, which gives meters per second, and that figure is then divided by the factor of the unit you asked for.
The factors are fixed. One kilometer per hour is 1 / 3.6 meters per second. One mile per hour is 0.44704 meters per second. One knot is 1852 / 3600 meters per second. One foot per second is 0.3048 meters per second.
Five units are offered: meter per second, kilometer per hour, mile per hour, knot and foot per second. Both boxes accept a value. Type in the lower one and the upper one answers, so the conversion runs in either direction without moving the units.
A result is shown to 12 significant digits. The arithmetic runs in your browser.
The answer is 62.1371192237 mph.
The same pair read the other way gives 60 mph as 96.56064 km/h. That second figure is exact rather than rounded, because the international mile is defined as 1,609.344 meters.
16 knots is 29.632 km/h, and 18.4124711684 mph.
A knot is one nautical mile per hour and a nautical mile is 1,852 meters, so the kilometer figure is exact as well. Only the mile figure carries a rounded tail.
62.1371192237 mph. One kilometer per hour is 0.621371192237 mph, so any figure in km/h can be multiplied by that number. 30 km/h is 18.6411357671 mph, 50 km/h is 31.0685596119 mph, and 120 km/h is 74.5645430685 mph.
Multiply by 3.6. One meter per second is 3.6 km/h and 10 m/s is 36 km/h. The other direction divides by 3.6, so one kilometer per hour is 0.277777777778 m/s and 100 km/h is 27.7777777778 m/s.
In miles per hour the same speed reads differently again. One meter per second is 2.23693629205 mph and 10 m/s is 22.3693629205 mph.
One knot is 1.852 km/h, 1.15077944802 mph and 0.514444444444 m/s. Twenty knots is 37.04 km/h. Read back the other way, 100 km/h is 53.9956803456 knots.
Meter per second, kilometer per hour, mile per hour, knot and foot per second, and any pair of them in either direction. One foot per second is 0.3048 m/s, and one meter per second is 3.28083989501 ft/s. For distances on their own rather than speeds, use the Length Converter.
Every unit here is defined by an exact number, so a conversion that lands on a short decimal is exact: 60 mph is exactly 96.56064 km/h, and 20 knots is exactly 37.04 km/h. Where it does not, the result is rounded to 12 significant digits.
Yes to the first, and no to the second. The application is kept in the browser after your first visit, so the page opens and converts with no connection. There is no account, nothing you type reaches a server, and no result is written down.
The mile per hour rests on the international yard and pound agreement of 1959, which fixed the yard at 0.9144 meters and made the mile exactly 1,609.344 meters. Every mile per hour figure on this page follows from that one definition.
The knot came from a rope. A log was thrown from a moving ship and the knots in its line were counted as they ran out over a measured time.
This page is one of nine converters that share a conversion field. The others include the Time Unit Converter and the Fuel Consumption Converter.