How do you convert knots to km/h?
Multiply the number of knots by 1.852. In your head, double it then take off 7 %: 20 knots gives 40 − 3 = 37 km/h, against an exact 37.04.
knots = km/h ÷ 1.852
Speeds and wind forces in knots and km/h
| 1 kn (one nautical mile per hour) | 1.9 km/h |
| 5 kn (light breeze) | 9.3 km/h |
| 10 kn | 18.5 km/h |
| 20 kn (sailboat downwind) | 37.0 km/h |
| 22 kn (container ship service speed) | 40.7 km/h |
| 34 kn (force 8, gale) | 63.0 km/h |
| 48 kn (force 10, storm) | 88.9 km/h |
| 64 kn (force 12, hurricane) | 118.5 km/h |
| 150 kn (aircraft approach) | 277.8 km/h |
| 480 kn (long-haul cruise) | 889.0 km/h |
| 1176 kn (Concorde, Mach 2.02) | 2178.0 km/h |
Show every value
- 1 kn = 1.852 km/h
- 2 kn = 3.704 km/h
- 3 kn = 5.556 km/h
- 4 kn = 7.408 km/h
- 5 kn = 9.26 km/h
- 6 kn = 11.112 km/h
- 7 kn = 12.964 km/h
- 8 kn = 14.816 km/h
- 9 kn = 16.668 km/h
- 10 kn = 18.52 km/h
- 11 kn = 20.372 km/h
- 12 kn = 22.224 km/h
- 13 kn = 24.076 km/h
- 14 kn = 25.928 km/h
- 15 kn = 27.78 km/h
- 16 kn = 29.632 km/h
- 17 kn = 31.484 km/h
- 18 kn = 33.336 km/h
- 19 kn = 35.188 km/h
- 20 kn = 37.04 km/h
- 21 kn = 38.892 km/h
- 22 kn = 40.744 km/h
- 23 kn = 42.596 km/h
- 24 kn = 44.448 km/h
- 25 kn = 46.3 km/h
- 26 kn = 48.152 km/h
- 27 kn = 50.004 km/h
- 28 kn = 51.856 km/h
- 29 kn = 53.708 km/h
- 30 kn = 55.56 km/h
- 31 kn = 57.412 km/h
- 32 kn = 59.264 km/h
- 33 kn = 61.116 km/h
- 34 kn = 62.968 km/h
- 35 kn = 64.82 km/h
- 36 kn = 66.672 km/h
- 37 kn = 68.524 km/h
- 38 kn = 70.376 km/h
- 39 kn = 72.228 km/h
- 40 kn = 74.08 km/h
- 41 kn = 75.932 km/h
- 42 kn = 77.784 km/h
- 43 kn = 79.636 km/h
- 44 kn = 81.488 km/h
- 45 kn = 83.34 km/h
- 46 kn = 85.192 km/h
- 47 kn = 87.044 km/h
- 48 kn = 88.896 km/h
- 49 kn = 90.748 km/h
- 50 kn = 92.6 km/h
- 51 kn = 94.452 km/h
- 52 kn = 96.304 km/h
- 53 kn = 98.156 km/h
- 54 kn = 100.008 km/h
- 55 kn = 101.86 km/h
- 56 kn = 103.712 km/h
- 57 kn = 105.564 km/h
- 58 kn = 107.416 km/h
- 59 kn = 109.268 km/h
- 60 kn = 111.12 km/h
- 61 kn = 112.972 km/h
- 62 kn = 114.824 km/h
- 63 kn = 116.676 km/h
- 64 kn = 118.528 km/h
- 65 kn = 120.38 km/h
- 66 kn = 122.232 km/h
- 67 kn = 124.084 km/h
- 68 kn = 125.936 km/h
- 69 kn = 127.788 km/h
- 70 kn = 129.64 km/h
- 71 kn = 131.492 km/h
- 72 kn = 133.344 km/h
- 73 kn = 135.196 km/h
- 74 kn = 137.048 km/h
- 75 kn = 138.9 km/h
- 76 kn = 140.752 km/h
- 77 kn = 142.604 km/h
- 78 kn = 144.456 km/h
- 79 kn = 146.308 km/h
- 80 kn = 148.16 km/h
- 81 kn = 150.012 km/h
- 82 kn = 151.864 km/h
- 83 kn = 153.716 km/h
- 84 kn = 155.568 km/h
- 85 kn = 157.42 km/h
- 86 kn = 159.272 km/h
- 87 kn = 161.124 km/h
- 88 kn = 162.976 km/h
- 89 kn = 164.828 km/h
- 90 kn = 166.68 km/h
- 91 kn = 168.532 km/h
- 92 kn = 170.384 km/h
- 93 kn = 172.236 km/h
- 94 kn = 174.088 km/h
- 95 kn = 175.94 km/h
- 96 kn = 177.792 km/h
- 97 kn = 179.644 km/h
- 98 kn = 181.496 km/h
- 99 kn = 183.348 km/h
- 100 kn = 185.2 km/h
- 125 kn = 231.5 km/h
- 150 kn = 277.8 km/h
- 175 kn = 324.1 km/h
- 200 kn = 370.4 km/h
- 225 kn = 416.7 km/h
- 250 kn = 463 km/h
- 275 kn = 509.3 km/h
- 300 kn = 555.6 km/h
- 325 kn = 601.9 km/h
- 350 kn = 648.2 km/h
- 375 kn = 694.5 km/h
- 400 kn = 740.8 km/h
- 425 kn = 787.1 km/h
- 450 kn = 833.4 km/h
- 475 kn = 879.7 km/h
- 500 kn = 926 km/h
- 550 kn = 1,018.6 km/h
- 600 kn = 1,111.2 km/h
- 650 kn = 1,203.8 km/h
- 700 kn = 1,296.4 km/h
- 750 kn = 1,389 km/h
- 800 kn = 1,481.6 km/h
- 850 kn = 1,574.2 km/h
- 900 kn = 1,666.8 km/h
- 950 kn = 1,759.4 km/h
- 1,000 kn = 1,852 km/h
- 1,500 kn = 2,778 km/h
- 2,000 kn = 3,704 km/h
- 2,500 kn = 4,630 km/h
- 3,000 kn = 5,556 km/h
- 3,500 kn = 6,482 km/h
- 4,000 kn = 7,408 km/h
- 4,500 kn = 8,334 km/h
- 5,000 kn = 9,260 km/h
- 5,500 kn = 10,186 km/h
- 6,000 kn = 11,112 km/h
- 6,500 kn = 12,038 km/h
- 7,000 kn = 12,964 km/h
- 7,500 kn = 13,890 km/h
- 8,000 kn = 14,816 km/h
- 8,500 kn = 15,742 km/h
- 9,000 kn = 16,668 km/h
- 9,500 kn = 17,594 km/h
- 10,000 kn = 18,520 km/h
The nautical mile has been exactly 1,852 meters since 1929, a value adopted by the International Hydrographic Conference. The knot follows from it: one nautical mile per hour. Methodology & sources.
Frequently asked questions
Why do shipping and aviation use knots?
Because one nautical mile equals one arcminute of latitude. On a chart, an hour at 10 knots reads directly as 10 arcminutes, with no conversion. That advantage vanishes in km/h, which is why the knot survives.
Where does the word knot come from?
From the chip log: a weighted line paid out behind the ship with knots tied at regular intervals. Sailors counted the knots that passed while a sandglass ran, and the count gave the speed directly. The instrument's name stuck to the unit.
Is a knot the same as a mile per hour?
No, and the gap is 15 %. A knot is 1.852 km/h, a mile per hour 1.609 km/h. Mixing them up on a flight plan or a sea route throws the time calculation badly off.
Why does an aircraft show two different speeds?
Because two speeds coexist. Airspeed, the one the aircraft is flown on, is read in knots against the air mass; ground speed, the one that decides the arrival time, adds the wind. A long-haul jet at 480 knots of airspeed shows 600 knots over the ground, 1,111 km/h, with a 120-knot jet stream behind it, and only 360 knots flying into it.
Has the nautical mile always been 1,852 metres?
No. The United Kingdom counted the Admiralty mile as 6,080 feet, 1,853.18 metres, until 1970, and the United States used 1,853.25 metres until 1954. The gap of just over a metre changes nothing at sea but explains the slightly different values printed on older charts.