# Knots Vs. MPH URL: https://sciencestruck.com/physics/knots-vs-mph Category: Physics Published: 2010-08-11T07:22:00 Updated: 2010-08-11T07:22:00 This article provides information about the comparison between speed units of Knots and Mph. People specifically with marine interests may know how speed is calculated with reference to ships and marine crafts. This unit used is called ‘knot’, and it can be considered as one of the larger units to calculate speed. Mph on the other hand is used to calculate speed on the land surface. ### Definition of Knots A knot is a unit of speed, and one knot is equal to one nautical mile per hour, or 1.151 miles per hour (approximately). Therefore, 1 knot = 1 nautical mile per hour 1 knot = 1.151 miles per hour Nautical relates to ships, shipping, navigation on water body, etc. Hence, a nautical mile is used only in shipping context. The abbreviation for knot may differ. The American and Canadian Maritime Authorities prefer the ‘kn’ symbol for knot, which is also accepted by the Institute of Electrical and Electronic Engineers. The other abbreviations are ‘kt’ (singular) and ‘kts’ (plural), which are commonly used by other countries. The International Hydrographic Organization also prefers the abbreviation ‘kn’ for knots, which includes all major seafaring nations. Knot is not only used for maritime, but also is used in air navigation and meteorology. The knot is not a part of SI units (International System of Units), but it is an accepted unit of measurement, and is used along with the SI unit system. ### Definition of Miles per Hour Miles per hour (Mph) is a unit of speed, which calculates the number of miles covered per hour. This is a standard unit to calculate speed in most of the countries, including The United States and United Kingdom. For laws pertaining to speed, it is used the most in several nations. ‘MPH’ or ‘mph’ is the common abbreviation used for this unit. It is also used to calculate the speed of ball in games like baseball, cricket, and tennis. 1 mph = 0.44704 m/s (meter per second) 1 mph = 1.609344 km/h (kilometer per hour) 1 mph = 0.868976 knots approximately ### Knots Vs. Mph Both Miles per hour and knots are number of units of distance, which is covered in a certain amount of time. 1 international knot = 1 nautical mile per hour = 1.852 kilometers per hour = 0.514 meters per second. ### Conversion from Knots to Mph **Knots** **Mph** 5 Knots 5.8 mph 10 Knots 11.5 mph 15 Knots 17.3 mph 20 Knots 23 mph 25 Knots 28.8 mph 30 Knots 34.6 mph 35 Knots 40.3 mph 40 Knots 46.1 mph 45 Knots 51.8 mph 50 Knots 57.6 mph 55 Knots 63.4 mph 60 Knots 69.1 mph 65 Knots 74.9 mph 70 Knots 80.6 mph 75 Knots 86.4 mph 80 Knots 92.2 mph 85 Knots 97.9 mph 90 Knots 103.7 mph 95 Knots 109.4 mph 100 Knots 115.2 mph 105 Knots 121 mph 110 Knots 126.7 mph 115 Knots 132.5 mph 120 Knots 138.2 mph 125 Knots 144 mph 130 Knots 149.8 mph 135 Knots 155.5 mph 140 Knots 161.3 mph 145 Knots 167 mph 150 Knots 172.8 mph The length of the internationally agreed nautical mile is 1,852m. The U.S. adopted the international definition in 1954, having previously used the U.S. nautical mile. Speed of tidal streams, wind, and river currents are also measured in knots.