Knots to Miles Per Hour (kn to mph)
1 knot equals 1.150779448 miles per hour (rounded).
How to convert knots to miles per hour
To convert knots to miles per hour, multiply the number of knots by 1.150779448. The factor is rounded to 10 significant digits. To go the other way, multiply miles per hour by 0.8689762419 (rounded).
miles per hour = knots × 1.150779448
Example: 10 knots = 11.50779448 miles per hour.
About these units
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
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
Related conversions
- Miles per hour to knots (reverse)
- Knots to meters per second
- Knots to kilometers per hour
- Knots to feet per second
- Knots to Mach
- Knots to speed of light
- Knots to centimeters per second
- Knots to millimeters per second
- Knots to kilometers per second
- Knots to kilometers per minute
- Knots to meters per minute
- Knots to inches per second
- Knots to feet per minute
- Meters per second to miles per hour
- Kilometers per hour to miles per hour
- Feet per second to miles per hour
- Mach to miles per hour
- Speed of light to miles per hour
- Centimeters per second to miles per hour
- Millimeters per second to miles per hour
- Kilometers per second to miles per hour
- Kilometers per minute to miles per hour
- Meters per minute to miles per hour
- Inches per second to miles per hour
- Feet per minute to miles per hour
See all speed units.