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Italiano1 knot = 1.852 km/h: the formula
To convert knots to km/h, multiply by 1.852: km/h = knots × 1.852. The factor is exact: a knot is one nautical mile per hour, and the nautical mile is defined as 1,852 m. Example: a 15-knot breeze is 15 × 1.852 = 27.78 km/h.
The converter on this page is already set to knots to km/h and opens on 1 kn = 1.852 km/h. The answer updates as you type, to six significant figures. The ⇄ "Swap units" button turns it into km/h to knots, and the "In every unit" table shows the same speed in mph and m/s: 1 kn = 1.15078 mph = 0.514444 m/s.
Knots to km/h conversion chart
| Knots | km/h | What it means |
|---|---|---|
| 1 | 1.85 | One nautical mile per hour |
| 11 | 20.37 | Start of Beaufort force 4, moderate breeze |
| 15 | 27.78 | Good sailing wind |
| 22 | 40.74 | Start of force 6, strong breeze |
| 28 | 51.86 | Start of force 7, near gale |
| 34 | 62.97 | Start of force 8, gale |
| 41 | 75.93 | Start of force 9, strong gale |
| 48 | 88.90 | Start of force 10, storm |
| 64 | 118.53 | Force 12, hurricane force |
| 100 | 185.20 | Small training aircraft in cruise |
| 250 | 463.00 | US speed limit below 10,000 ft |
| 480 | 888.96 | Airliner cruise through the air, roughly |
Weather at sea, boats and planes
Wind and the Beaufort scale
Marine forecasts, including the UK Shipping Forecast, give wind in Beaufort forces, and the thresholds are set in knots. A gale, force 8, runs from 34 to 40 knots, which is 62.97 to 74.08 km/h. Force 12 starts at 64 knots, 118.53 km/h, where a tropical storm becomes a category 1 hurricane.
On the water
A knot is one nautical mile in an hour, so speed and distance on a chart work together without converting. A container ship at 20 knots covers 480 nautical miles a day, or 888.96 km, at a speed of 37.04 km/h.
In the air
Pilots and air traffic control work in knots. An airliner lands at around 140 knots, about 259 km/h, and cruises at very roughly 480 knots through the air, about 889 km/h. Below 10,000 ft, US rules cap most aircraft at 250 knots, which is exactly 463 km/h.
Mental math
Double it, then take off 7.4%: that is exactly 1.852. For 30 knots, 60 minus 4.44 gives 55.56 km/h. Doubling and taking off 10% gives 54, 2.8% low.
Frequently asked questions
How fast is 10 knots in km/h?
18.52 km/h, or 11.51 mph. That is the top of force 3, a gentle breeze, which runs from 7 to 10 knots.
Why is a nautical mile 1,852 meters?
It is close to one minute of arc of latitude on the Earth. International agreement rounded it to exactly 1,852 m.
Is a knot faster than a mile per hour?
Yes. One knot is 1.15078 mph, because a nautical mile is longer than a statute mile of 1,609.344 m.