Converters Knots to kilometres per hour
Convert knots to km/h and mph with the exact factor, plus a Beaufort wind scale reference and why aviation still uses them.
1 kn = 1.852 km/h
kilometres per hour = knots × 1.852
knots to kilometres per hour
| kn | km/h |
|---|---|
| 1 | 1.852 |
| 2 | 3.704 |
| 3 | 5.556 |
| 4 | 7.408 |
| 5 | 9.26 |
| 10 | 18.52 |
| 15 | 27.78 |
| 20 | 37.04 |
| 25 | 46.3 |
| 50 | 92.6 |
| 75 | 138.9 |
| 100 | 185.2 |
| 500 | 926 |
| 1,000 | 1,852 |
One knot is exactly 1.852 kilometres per hour.
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Cite this page
Reembun. (2026, July 28). Knots to kilometres per hour. https://reembun.com/convert/speed/knots-to-kmh
How to use it
Type the speed in knots
Kilometres per hour appear as you type.
Go the other way
Swap units converts km/h back into knots.
Copy it or read the table
A knot is one nautical mile an hour, which is exactly 1.852 kilometres per hour. That is a definition, so nothing here is rounded on the way in.
The formulas
km/h = knots × 1.852
mph = knots × 1.15078
knots = km/h ÷ 1.852Exact by definition. The nautical mile was fixed at exactly 1,852 metres by international agreement in 1929, chosen as a round metric approximation of one minute of latitude.
Quick reference
| Knots | km/h | mph |
|---|---|---|
| 1 | 1.85 | 1.15 |
| 5 | 9.26 | 5.75 |
| 10 | 18.52 | 11.51 |
| 15 | 27.78 | 17.26 |
| 20 | 37.04 | 23.02 |
| 30 | 55.56 | 34.52 |
| 50 | 92.60 | 57.54 |
| 100 | 185.20 | 115.08 |
The Beaufort wind scale
| Force | Knots | Description | At sea |
|---|---|---|---|
| 0 | <1 | Calm | Mirror-like |
| 3 | 7-10 | Gentle breeze | Large wavelets |
| 5 | 17-21 | Fresh breeze | Moderate waves, spray |
| 6 | 22-27 | Strong breeze | Large waves, white foam |
| 7 | 28-33 | Near gale | Sea heaps up |
| 8 | 34-40 | Gale | Moderately high waves |
| 10 | 48-55 | Storm | Very high waves |
| 12 | 64+ | Hurricane force | Sea completely white |
Force 8 at 34 knots is 63 km/h, which is where small craft warnings are typically issued.
Typical speeds
| Vessel or aircraft | Knots | km/h |
|---|---|---|
| Cruising sailing yacht | 5-8 | 9-15 |
| Container ship | 20-24 | 37-44 |
| Cruise ship | 20-24 | 37-44 |
| Aircraft carrier | 30+ | 56+ |
| Cessna 172 | 120 | 222 |
| Boeing 737 cruise | 450 | 833 |
| Concorde cruise | 1,150 | 2,130 |
Why the unit survives
A nautical mile is one minute of arc along a meridian. That means a navigator reading a chart can measure distance directly against the latitude scale printed on its edge. Sixty minutes of latitude is 60 nautical miles, always, anywhere.
No metric unit has that property, because the metre was defined from a fraction of the Earth’s quadrant rather than from an angular subdivision. Replacing knots would mean giving up the one thing that makes chart navigation arithmetic-free, which is why every attempt to metricate aviation and maritime speed has failed.
Aviation compounds the inconsistency: altitude is in feet, distance in nautical miles, speed in knots, and runway visual range in metres. A few countries including China and Russia use metres for altitude, which requires conversion tables in the cockpit when crossing the boundary, a known and actively managed source of risk.
Common questions
What is a knot?
One nautical mile per hour, which is exactly 1.852 km/h or about 1.151 mph. The nautical mile is one minute of arc along a meridian, which is what makes it useful for navigation: one minute of latitude on a chart is one nautical mile, with no conversion needed.
Why do aviation and shipping still use knots?
Because of that geometric relationship. A navigator can read distance directly off a chart's latitude scale. No metric unit offers that, and the cost of changing a global system that works is far higher than the inconsistency costs.
Where does the name come from?
From the chip log, a weighted board on a line with knots tied at fixed intervals. Sailors let it run out for a measured time and counted the knots that passed. The unit is named after the physical knots in the rope.
How do I estimate knots to km/h?
Multiply by 2 and subtract about 7%. For 20 knots: 40 minus 3 gives 37 km/h against a true 37.04. For knots to mph, add roughly 15%.
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