Knots to MPH Converter
Convert knots to miles per hour (and mph to knots) with a live knots to mph calculator. One knot equals 1.1508 mph. Use the quick mode for knots and mph, or switch to multi-unit mode for knots, mph, km/h, m/s, and ft/s, with adjustable precision and a step-by-step breakdown of every calculation.
Knots to MPH Calculator
Knots to MPH Formula
Both factors are exact by definition: the international nautical mile is defined as exactly 1,852 meters, and the international statute mile as exactly 1,609.344 meters. The ratio 1.852 / 1.609344 = 1.1507794480235... is therefore exact, not a rounded constant.
Knots to MPH Chart
Quick-reference knots to mph table of popular values, computed from the exact factor 1.1507794480.
Popular lookups: 10 knots to mph = 11.5078 mph, 20 knots to mph = 23.0156 mph, 30 knots to mph = 34.5234 mph, 50 knots to mph = 57.5390 mph, 100 knots to mph = 115.0779 mph.
| Knots | MPH | Knots | MPH |
|---|---|---|---|
| 1 | 1.1508 | 60 | 69.0468 |
| 2 | 2.3016 | 75 | 86.3085 |
| 5 | 5.7539 | 100 | 115.0779 |
| 10 | 11.5078 | 150 | 172.6169 |
| 15 | 17.2617 | 200 | 230.1559 |
| 20 | 23.0156 | 250 | 287.6949 |
| 25 | 28.7695 | 300 | 345.2338 |
| 30 | 34.5234 | 500 | 575.3897 |
| 40 | 46.0312 | 50 | 57.5390 |
What Do These Speeds Mean in MPH?
Typical uses of a knots to mph conversion: boat speed from knots to mph, ship speed from knots to mph, wind speed from knots to mph, and airplane speed from knots to mph.
Boat and ship speeds
| Cruising sailing yacht (7 kn) | 8.0555 mph |
| Container ship (24 kn) | 27.6187 mph |
| Planing motorboat (25 kn) | 28.7695 mph |
| Fast ferry (30 kn) | 34.5234 mph |
Marine speedometers and GPS units report knots; road users think in mph. A 25-knot boat is barely faster than a 25 mph car zone.
Airplane speeds
| Light aircraft, e.g. Cessna 172 (110 kn) | 126.5857 mph |
| Helicopter cruise (130 kn) | 149.6013 mph |
| Regional jet (350 kn) | 402.7728 mph |
| Airliner cruise (450 kn) | 517.8508 mph |
Aviation worldwide uses knots for airspeed. A 450-knot airliner cruises at about 518 mph true airspeed.
Wind: Beaufort scale in mph
| Force | Description | Knots | MPH |
|---|---|---|---|
| 0 | Calm | <1 | <1 |
| 1 | Light air | 1-3 | 1-3 |
| 2 | Light breeze | 4-6 | 5-7 |
| 3 | Gentle breeze | 7-10 | 8-12 |
| 4 | Moderate breeze | 11-16 | 13-18 |
| 5 | Fresh breeze | 17-21 | 20-24 |
| 6 | Strong breeze | 22-27 | 25-31 |
| 7 | Near gale | 28-33 | 32-38 |
| 8 | Gale | 34-40 | 39-46 |
| 9 | Strong gale | 41-47 | 47-54 |
| 10 | Storm | 48-55 | 55-63 |
| 11 | Violent storm | 56-63 | 64-72 |
| 12 | Hurricane | 64+ | 73.65+ |
MPH ranges are the exact knot boundaries converted at 1.1507794480 and rounded to the nearest mph.
Worked Examples
Example 1: boat speed, 22 knots to mph
A powerboat GPS reads 22 knots. Convert: 22 × 1.852 = 40.744 km/h, then 40.744 ÷ 1.609344 = 25.3171 mph. Shortcut: 22 × 1.1507794480 = 25.3171 mph. The boat is doing just over 25 mph.
Example 2: wind speed, 15 knots to mph
A marine forecast reports a 15-knot wind. Convert: 15 × 1.852 = 27.78 km/h, then 27.78 ÷ 1.609344 = 17.2617 mph. Shortcut: 15 × 1.1507794480 = 17.2617 mph. That is a Beaufort force 4 moderate breeze.
Example 3: reverse, 55 mph to knots
A driver doing 55 mph wants the equivalent in knots. Convert: 55 × 1.609344 = 88.51392 km/h, then 88.51392 ÷ 1.852 = 47.7937 knots. Shortcut: 55 ÷ 1.1507794480 = 47.7937 knots.
Example 4: multi-unit, 40 knots to km/h, m/s, ft/s
40 knots × 1.852 = 74.08 km/h. In meters per second: 74.08 ÷ 3.6 = 20.577778 m/s. In feet per second: 74.08 ÷ 1.09728 = 67.5124 ft/s. And in mph: 40 × 1.1507794480 = 46.0312 mph.
Frequently Asked Questions
How fast is 1 knot in mph?
One knot equals 1.1508 miles per hour (mph), or exactly 1.1507794480 mph. So if a boat is moving at 1 knot, it is traveling at about 1.15 mph. A knot is slightly faster than a mile per hour because a nautical mile (1.852 km) is longer than a statute mile (1.609344 km).
What is the formula to convert knots to mph?
To convert knots to mph, multiply the number of knots by 1.1507794480. The full formula is: mph = knots x 1.852 / 1.609344. For example, 20 knots x 1.1507794480 = 23.0156 mph.
How do you convert mph to knots?
To convert mph to knots, multiply the mph value by 0.8689762419, which is the same as dividing by 1.1507794480. The full formula is: knots = mph x 1.609344 / 1.852. For example, 60 mph x 0.8689762419 = 52.1386 knots.
How much is 10 knots in mph?
10 knots equals 11.5078 mph. Multiply 10 by the conversion factor 1.1507794480 to get 11.5078 miles per hour.
How much is 20 knots in mph?
20 knots equals 23.0156 mph. A 20-knot boat speed is roughly the pace of a car driving through a 25 mph residential zone.
How much is 30 knots in mph?
30 knots equals 34.5234 mph. Many fast powerboats and ferries cruise at around 30 knots, about 34.5 mph.
How much is 50 knots in mph?
50 knots equals 57.5390 mph. That is faster than highway driving in many countries and close to gale-force wind speeds on the Beaufort scale.
How much is 100 knots in mph?
100 knots equals 115.0779 mph. Light aircraft typically cruise between 100 and 130 knots, which is roughly 115 to 150 mph.
Is a knot faster than a mile per hour?
Yes. One knot is 1.1508 miles per hour, so a knot is about 15.08 percent faster than a mile per hour. Going 10 knots means going 11.5078 mph.
Why do boats and planes use knots instead of mph?
Knots are based on the nautical mile, which equals exactly 1.852 kilometers, or one minute of latitude. Because nautical charts are drawn in degrees of latitude, speed in knots converts directly into distance traveled on the chart: one knot for one hour means one minute of latitude. Mph is a land-based unit tied to the statute mile, which has no such navigation relationship.
What does 1 knot mean in wind speed?
A wind speed of 1 knot means the air is moving at 1.1508 mph, or 1.852 km/h. Marine forecasts use knots: for example, a 15-knot wind equals 17.2617 mph, which is a Beaufort force 4 moderate breeze.
How fast is 60 mph in knots?
60 mph equals 52.1386 knots. Multiply 60 by 0.8689762419, or divide 60 by 1.1507794480, to get 52.1386 knots.
Knots vs mph: what is the difference?
A knot is a unit of speed equal to one nautical mile per hour (1.852 km/h), while mph means statute miles per hour (1.609344 km/h). The key difference: 1 knot = 1.1508 mph, so a knot is the larger unit. Knots are the standard in marine and aviation navigation; mph is the standard for road speeds in the US and UK.
How many knots is 25 mph?
25 mph equals 21.7244 knots. Divide 25 by 1.1507794480, or multiply by 0.8689762419, to get 21.7244 knots.
Where can I find a knots to mph chart?
The conversion table on this page is a ready-made knots to mph chart covering 1 to 500 knots, from 1.1508 mph up to 575.3897 mph. For any value not in the chart, use the converter above with adjustable precision from 0 to 10 decimals.
Methodology
Definitions used
1 knot is defined as exactly 1.852 km/h (the international nautical mile, exactly 1,852 meters). 1 mph is defined as exactly 1.609344 km/h (the international statute mile, exactly 1,609.344 meters). All five units in multi-unit mode convert through km/h: knots x 1.852, mph x 1.609344, km/h x 1, m/s x 3.6, ft/s x 1.09728. The widely used factor 1 knot = 1.1507794480 mph is the exact ratio 1.852 / 1.609344.
Rounding
Displayed results round half up to the selected precision (0 to 10 decimals). Internal calculations keep full floating-point precision before rounding, so changing precision never changes the underlying value.
Beaufort mph ranges
The Beaufort knot boundaries are the standard published ranges. The mph column is each boundary converted at the exact factor 1.1507794480 and rounded to the nearest mph.
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