Knots to mph Converter
If you're wondering how much a knot is, you're in the right place  this knots to mph converter can help you in clearing up your doubts. Type the value into the calculator, and in the blink of an eye, you'll get the answer  equivalent in mph, ft/s, m/s, and km/h. As our calculators are flexible tools, you can also convert mph to knot or any other wind speed unit. Keep reading if you want to know how many mph a knot is or how fast it is. Also, you'll find an informative wind speed chart and all the formulas behind the wind speed unit conversions.
How many mph is a knot and how fast is it? What is a nautical mile?
One knot is defined as 1 nautical mile per hour and:
 1.15078 miles per hour (approximately);
 1.852 kilometers per hour (exactly);
 1.68781 feet per second (approximately); and
 0.51444 meters per second (approximately).
Nautical miles and knots are the units used in meteorology, aviation, and nautical navigation. What's the difference between them? A nautical mile measures the distance, and a knot measures the speed.
One nautical mile historically was defined as one minute of latitude (1/60 of a degree of latitude), which is 1.852 kilometers. That's the average value, as the Earth is not a perfect sphere but a geoid.
Conversion formulas. Knots to mph and mph to knots
To convert between speed units, you can use our knots to mph converter or perform the conversion manually using the formulas:
 knots to mph and mph to knots

V(knots) = 0.868976 × V(mph)
; 
V(mph) = 1.150779 × V(knots)
;
 knots and km/h

V(knots) = 0.539957 × V(km/h)

V(km/h) = 1.852 × V(knots)
 knots and ft/s

V(knots) = 0.592484 × V(ft/s)

V(ft/s) = 1.687810 × V(knots)
 knots and m/s

V(knots) = 1.943844 × V(m/s)

V(m/s) = 0.514444 × V(knots)
If you need conversion between other units (as there are 20 permutations and we present only 8 of them), take the coefficients from this table:
m/s  km/h  mph  knot  ft/s  

1 m/s =  1  3.6  2.236936  1.943844  3.280840 
1 km/h =  0.277778  1  0.621371  0.539957  0.911344 
1 mph =  0.44704  1.609344  1  0.868976  1.466667 
1 knot =  0.514444  1.852  1.150779  1  1.687810 
1 ft/s =  0.3048  1.09728  0.681818  0.592484  1 
Wind speed chart
Knowing how to convert knots to mph may be useful in many situations, such as:
 Determining the boat speeds and airspeeds, be sure to check our true airspeed calculator).
 Expressing tidal streams, river currents, and wind speeds.
 Finding the optimal conditions for windsurfing or kiteboarding (630 knots is a range usually used, depending on the body weight, kite size, and how skilled you are). Check our kiteboarding calculator to become more skilled!
With this wind speed chart, you can assess the prevailing conditions and even estimate them on the Beaufort scale:
Description  Range  Beaufort number  knots  mph  km/h  ft/s  m/s 

Calm  <1 mph  0  0  0  0  0  0 
Light air  13 mph  1  2.50  2.88  4.63  4.22  1.29 
Light breeze  47 mph  2  5.00  5.75  9.26  8.44  2.57 
Gentle breeze  812 mph  3  7.50 10.00  8.63 11.51  13.89 18.52  12.66 16.88  3.86 5.14 
Moderate breeze  1318 mph  4  12.50 15.00  14.38 17.26  23.15 27.78  21.10 25.32  6.43 7.72 
Strong breeze  2531 mph  6  22.50 25.00 27.50  25.89 28.77 31.65  41.67 46.30 50.93  37.98 42.20 46.42  11.57 12.86 14.15 
Moderate gale  3238 mph  7  30.00 32.50  34.52 37.40  55.56 60.19  50.63 54.85  15.43 16.72 
Fresh gale  3946 mph  8  35.00 37.50 40.00  40.28 43.15 46.03  64.82 69.45 74.08  59.07 63.29 67.51  18.01 19.29 20.58 
Strong gale  4754 mph  9  42.50 45.00 47.50  48.91 51.79 54.66  78.71 83.34 87.97  71.73 75.95 80.17  21.86 23.15 24.44 
Whole gale (storm)  5563 mph  10  50.00 52.50 55.00  57.54 60.42 63.29  92.60 97.23 101.86  84.39 88.61 92.83  25.72 27.01 28.29 
Violent storm  6473 mph  11  57.50 60.00 62.50  66.17 69.05 71.92  106.49 111.12 115.75  97.05 101.27 105.49  29.58 30.87 32.15 
Hurricane 
 12  65.00 67.50 70.00  74.80 77.68 80.55  120.38 125.01 129.64  109.7 113.93 118.15  33.44 34.72 36.01 
How to use knots to mph converter: 40 knots to mph example
If you are wondering how fast a knot is  or maybe it is 40 knots you wish to know  have a look at this short stepbystep example:

Think about the unit you want to convert. Let's assume we want to change 40 knots into miles per hour.

Type the value into the proper box. In our case, we need to enter 40 into the first part of the tool.

That's it! Our knots to mph converter did the job! Now we know that 40 knots is equal to 46.03 mph. That's quite a lot!
FAQ
How many mph is 50knot winds?
Wind blowing at 50 knots is equal to 57.54 mph. Since 1 knot equals 1 nautical mile, we can also deduce that 50 knots is the same as 50 nautical miles.
Why do ships use knots instead of mph?
Using knots for navigating nautical miles is more convenient than other statute distance units. 1 nautical mile is equal to 1 minute of latitude. And since the ships travel the earth's curvature, it is fitting to use knots over mph.
Interestingly, a knot is also the desired unit of measurement for fluids in motion.
How fast is 12 knots in miles?
12 knots are approximately 13.81 miles per hour. You can convert from knots to miles using the formula:
Speed in mph = 1.150779 × Speed in knots
12 knots are also equal to 6.173 meters per second.
How can I convert knots to mph?
Converting from knots to miles per hour (mph) is straightforward, especially if you know the conversion factor.
 Note down the speed in knots.
 Multiply knots by the conversion factor for mph, 1.150779.
 The result is the speed in miles per hour.