Kilometers per Hour to Knots
Convert kilometers per hour (km/h) to knots (kn). Both measure velocity, and the conversion comes up in driving, aviation, sports work.
The Formula
``
knots = kilometers per hour × 0.539956803456
kilometers per hour = knots × 1.852
`
One kilometers per hour is 0.539957 knots, and one knot is 1.852 kilometers per hour.
Conversion Table
| Kilometers per Hour | Knots |
|---|---|
| 1 km/h | 0.539957 kn |
| 2 km/h | 1.0799 kn |
| 5 km/h | 2.6998 kn |
| 10 km/h | 5.3996 kn |
| 25 km/h | 13.4989 kn |
| 50 km/h | 26.9978 kn |
| 100 km/h | 53.9957 kn |
| 500 km/h | 269.9784 kn |
| 1,000 km/h | 539.9568 kn |
The Other Direction
| Knots | Kilometers per Hour |
|---|---|
| 1 kn | 1.852 km/h |
| 2 kn | 3.704 km/h |
| 5 kn | 9.26 km/h |
| 10 kn | 18.52 km/h |
| 25 kn | 46.3 km/h |
| 50 kn | 92.6 km/h |
| 100 kn | 185.2 km/h |
| 500 kn | 926 km/h |
| 1,000 kn | 1,852 km/h |
What Each Unit Is
Kilometers per Hour (km/h) — kilometres travelled per hour, equal to 1/3.6 m/s. The road-speed unit in almost every country outside the US and UK.
Knots (kn) — one nautical mile per hour, or exactly 1.852 km/h. From the knots in a line paid out behind a ship: sailors counted knots passing in a fixed time to read speed.
A Sense of Scale
Urban limits are 30–50 km/h- Motorways are 100–130 km/h
- A cyclist cruises at 20 km/h
- An airliner cruises at 450–500 knots
- A hurricane starts at 64 knots
Doing It in Your Head
Multiply by 6, then divide by 11. That is off by 1.02% — close enough to judge a
distance, a weight or a price, and not close enough to sign off on a drawing.
Exact Mental shortcut 5.3996 kn 5.4545 kn 53.9957 kn 54.5455 kn
Precision
The factor 0.539956803456 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
Watch Out For
- Never say "knots per hour" — the "per hour" is already in the unit.
In Code
`javascript
const kilometerPerHourToKnot = (value) => value * 0.539956803456;
``
Where This Conversion Comes Up
- Driving
- Aviation
- Sports
- Shipping
- Weather
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 km/h with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 km/h becomes | Error |
|---|---|---|---|
| 0 | 1 | 137 | 85.2000% |
| 1 | 0.5 | 68.5 | 7.4000% |
| 2 | 0.54 | 73.98 | 0.0080% |
| 3 | 0.54 | 73.98 | 0.0080% |
| 4 | 0.54 | 73.98 | 0.0080% |
The right number of significant figures is set by your input, not by the converter. If you measured kilometers per hour to three significant figures, the answer in knots is only good to three — writing more digits claims precision the measurement never had.