About the Knots to MPH
This knots to mph converter changes a speed in knots — nautical miles per hour — into miles per hour, kilometres per hour and metres per second. You can also start from mph, km/h or m/s to find the speed in knots, so one page covers both directions.
Knots are the standard unit for boat speed, aircraft airspeed and wind speed in marine and aviation forecasts. Sailors, pilots, drone flyers, anglers checking a marine forecast and anyone reading a hurricane advisory can use it to translate those numbers into the road-speed units they feel more at home with.
A knot is one nautical mile (exactly 1,852 m) per hour, while a statute mile is 1,609.344 m. That makes 1 knot about 1.15078 mph or exactly 1.852 km/h. For a quick mental estimate, add 15% to knots to get mph.
With the default inputs, the miles per hour is 23.016 mph. Change any value above to recalculate instantly.
How to use the knots to mph
- 1Enter the speed.
- 2Choose the unit you are converting from — knots by default.
- 3Read the speed in mph, plus km/h, knots and m/s.
- 4Use the table for common boat, wind and aircraft speeds.
Formula and method
A knot is one nautical mile per hour and a nautical mile is defined as exactly 1,852 metres. A statute mile is exactly 1,609.344 metres, so one knot is 1,852 ÷ 1,609.344 ≈ 1.150779 mph, and exactly 1.852 km/h.
To support every direction, the tool converts your speed to metres per second first (1 kn = 0.514444 m/s, 1 mph = 0.44704 m/s, 1 km/h = 0.277778 m/s) and then divides by the size of each target unit.
- kn
- Knots — nautical miles (1,852 m) per hour
- mph
- Statute miles (1,609.344 m) per hour
- km/h
- Kilometres per hour
Worked examples
A 20-knot boat
20 × 1.150779 = 23.02 mph. In metric terms 20 × 1.852 = 37.04 km/h, or 10.29 m/s.
60 mph wind in knots
60 mph ÷ 1.150779 = 52.14 knots — storm force on the Beaufort scale. It is also 96.56 km/h.
100 km/h in knots
100 ÷ 1.852 = 54.0 knots, which is 62.14 mph.
Frequently asked questions
How many mph is 1 knot?+
One knot is about 1.150779 mph, because a nautical mile (1,852 m) is longer than a statute mile (1,609.344 m). It is exactly 1.852 km/h.
Why do boats and planes use knots?+
A nautical mile is based on one minute of latitude, so distances on nautical and aeronautical charts line up directly with knots. That makes navigation calculations simpler.
How do I convert mph to knots?+
Divide mph by 1.150779, or multiply by 0.868976. For example, 30 mph is 26.07 knots.
How fast is 30 knots?+
30 knots is 34.52 mph or 55.56 km/h — a fast speed for a motorboat and a near-gale wind on the Beaufort scale.
Is knots per hour correct?+
No. A knot is already a speed (nautical miles per hour), so "knots per hour" would be an acceleration. Just say the boat is doing 15 knots.