Knots to Km/h
Type a speed in knots to get km/h. A knot is one nautical mile per hour, and the nautical mile is exactly 1,852 m, so 1 kn is exactly 1.852 km/h.
Formula: km/h = kn × 1.852
- Knot
- Also called kn · kt · nautical mile per hour
- One nautical mile per hour. The nautical mile is exactly 1,852 m, so one knot is exactly 1.852 km/h.
Knots to km/h table
| Knots (kn) | Kilometers per hour (km/h) |
|---|---|
| 1 | 1.852 |
| 2 | 3.704 |
| 3 | 5.556 |
| 4 | 7.408 |
| 5 | 9.26 |
| 6 | 11.112 |
| 7 | 12.964 |
| 8 | 14.816 |
| 9 | 16.668 |
| 10 | 18.52 |
| Knots (kn) | Kilometers per hour (km/h) |
|---|---|
| 12 | 22.224 |
| 15 | 27.78 |
| 20 | 37.04 |
| 25 | 46.3 |
| 30 | 55.56 |
| 40 | 74.08 |
| 50 | 92.6 |
| 60 | 111.12 |
| 75 | 138.9 |
| 100 | 185.2 |
Why ships and aircraft use knots
A nautical mile was first meant as one minute of latitude, so a navigator could read distances straight off a chart's side scale. The modern value of 1,852 m was agreed internationally in 1929, and NIST lists it as exact in SP 811. Marine and aviation forecasts give wind in knots for the same reason.
Sea charts still carry a latitude scale along their sides, and one minute on it is roughly one nautical mile, so navigators can measure distances with dividers.
Do
- Keep wind and boat speeds in knots when you read marine forecasts; the warnings use them.
- Convert to km/h when you compare with road speeds or a weather app.
Avoid
- Treating a knot as one mile per hour. It is about 15 % faster.
- Writing knots per hour. A knot is already a speed.
Knots, km/h and mph side by side
One knot is 1.852 km/h and about 1.151 mph, so 20 kn is 37.04 km/h or 23.02 mph. In aviation the cockpit often shows indicated airspeed, which differs from ground speed with wind and altitude, but the unit conversion is the same.
For miles per hour, use knots to mph; for road speeds, km/h to mph.
Most sailing boats stay below 10 kn, about 18.5 km/h, while large cargo ships typically cruise at roughly 15 to 25 kn, or 28 to 46 km/h. Aircraft are far faster: an airliner on approach at 140 kn is doing about 259 km/h.
Hurricane and storm warnings in many countries list wind in knots alongside km/h, so having both figures to hand helps when you compare reports.
Knots to km/h questions
What is one knot in km/h?
Exactly 1.852 km/h.
What is 30 knots in km/h?
30 × 1.852 = 55.56 km/h.
Why is it called a knot?
Sailors once measured speed with a log line, a rope with knots tied at even spacing. They counted how many knots ran out over a set time, and the count became the speed.
How do I convert km/h to knots?
Divide by 1.852. 100 km/h is 54 kn.