Formula to convert knots to mph: # kts * 1.15 = miles per hour. Formula to convert mph to knots: # mph * 0.87 = knots. Since the SI unit of speed happens to be meters per second (m/s), it might also be helpful to know how to convert wind speeds to these units.Why is wind speed measured in knots?
As a general rule in the US, wind speeds over land are expressed in miles per hour, while those over water are expressed in knots (largely because knots were invented over a water surface). Since meteorologists deal with winds over both surfaces, they adopted knots for the for the sake of consistency.How fast is a wind knot?
The surface wind speed in knots is multiplied by 1.15 to get the speed in miles per hour. A 100 knot wind is equal to 115 miles per hour while a 10 knot wind is equal to 11.5 miles per hour. Therefore, the stronger the wind the greater the difference between the numerical value of miles per hour and knots.