How to Convert Kilometres per hour to Knots (km/h to kn)
Speed conversions come up with expressway limits in km/h, foreign car specs in mph and wind speeds reported in knots by the Meteorological Service. This guide shows how to convert kilometres per hour into knots by hand, with examples and a quick-reference table.
The conversion
To convert kilometres per hour to knots, multiply the value by 0.5399572699. To go the other way, divide by the same number (or multiply by 1.8519984). For a quick estimate, multiply by about 0.54.
Knots = kilometres per hour × 0.5399572699
Worked examples
- 3 km/h = 1.6199 kn
- 12.5 km/h = 6.7495 kn
- 75 km/h = 40.4968 kn
Kilometres per hour to Knots table
| Kilometres 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 |
| 20 km/h | 10.7991 kn |
| 25 km/h | 13.4989 kn |
| 50 km/h | 26.9979 kn |
| 100 km/h | 53.9957 kn |
| 250 km/h | 134.9893 kn |
| 500 km/h | 269.9786 kn |
| 1,000 km/h | 539.9573 kn |
Common questions
Is km/h to kn exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Knots to Kilometres per hour converter.
Mistakes to avoid
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Background
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
For any value, use the Kilometres per hour to Knots Converter or browse all speed converters.
Run your own numbers: Kilometres per hour to Knots Converter