Miles Per Hour to Knots (mph to kn)
1 mile per hour equals 0.8689762419 knots (rounded).
How to convert miles per hour to knots
To convert miles per hour to knots, multiply the number of miles per hour by 0.8689762419. The factor is rounded to 10 significant digits. To go the other way, multiply knots by 1.150779448 (rounded).
knots = miles per hour × 0.8689762419
Example: 10 miles per hour = 8.689762419 knots.
About these units
Mile Per Hour (mph)
Exactly 0.44704 m/s. The unit for road speeds in the US, UK and a few other countries.
Early British motoring law is the best window into this unit. The 1861 Locomotive Act set a limit of 10 mph for light locomotives. The 1865 Red Flag Act cut it to 4 mph in the country and 2 mph in towns, with a person walking ahead with a flag. The Locomotives on Highways Act of 1896 raised it to 14 mph, and the Motor Car Act of 1903 to 20 mph. In 1931 all limits for cars were abolished, and 30 mph in built-up areas returned in 1935.
The mile per hour combines the mile, set at 5,280 feet in Elizabeth I's reign, with the hour, and it equals exactly 0.44704 m/s or 1.609344 km/h. The United Kingdom and United States use it on roads, along with several smaller countries, mostly territories or former territories of those two, and the US, Canada and Ireland use it for rail. Sports such as cricket, tennis and baseball quote ball speeds in it. Aviation and shipping prefer knots, about 0.869 of one mph each.
1 mile per hour = 0.44704 meters per second (exactly).
Sources: Wikipedia: Miles per hour; Wikipedia: Speed limits in the United Kingdom; Wikipedia: Mile
Knot (kn)
One nautical mile per hour, exactly 1.852 km/h. The unit of speed for ships, aircraft and wind.
Knots in a rope really were counted. Before the mid-nineteenth century, sailors threw a weighted wooden board, the chip, off the stern on a line called the log-line. The line carried knots at regular intervals, and a sailor counted how many passed through his fingers while another timed the run with a sandglass. William Bourne's A Regiment for the Sea, printed in 1574, is the first known description, and many ships spaced knots 8 fathoms, about 14.6 meters, apart with a glass of roughly half a minute.
Today a knot is one nautical mile per hour, exactly 1,852 meters per hour, about 1.151 mph or 0.514 m/s. A ship making 1 knot along a meridian covers about one minute of latitude per hour, which is why charts and the unit fit together. It is not an SI unit, and the symbol is kn, though kt is common in aviation. Saying knots per hour is wrong, since that would describe acceleration. The US moved civil aircraft standards to nautical miles and knots in 1969, and winds and currents are also quoted in them.
1 knot = 0.5144444444 meters per second (approximately).
Sources: Wikipedia: Knot (unit); Wikipedia: Chip log; NIST Guide to the SI, Appendix B.8: conversion factors
Related conversions
- Knots to miles per hour (reverse)
- Miles per hour to meters per second
- Miles per hour to kilometers per hour
- Miles per hour to feet per second
- Miles per hour to Mach
- Miles per hour to speed of light
- Miles per hour to centimeters per second
- Miles per hour to millimeters per second
- Miles per hour to kilometers per second
- Miles per hour to kilometers per minute
- Miles per hour to meters per minute
- Miles per hour to inches per second
- Miles per hour to feet per minute
- Meters per second to knots
- Kilometers per hour to knots
- Feet per second to knots
- Mach to knots
- Speed of light to knots
- Centimeters per second to knots
- Millimeters per second to knots
- Kilometers per second to knots
- Kilometers per minute to knots
- Meters per minute to knots
- Inches per second to knots
- Feet per minute to knots
See all speed units.