How to Convert Knots to Kilometres per hour (kn to km/h)
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 knots into kilometres per hour by hand, with examples and a quick-reference table.
The conversion
To convert knots to kilometres per hour, multiply the value by 1.8519984. To go the other way, divide by the same number (or multiply by 0.5399572699). For a quick estimate, multiply by about 1.9.
Kilometres per hour = knots × 1.8519984
Worked examples
- 3 kn = 5.556 km/h
- 12.5 kn = 23.15 km/h
- 75 kn = 138.8999 km/h
Knots to Kilometres per hour table
| Knots | Kilometres 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 |
| 20 kn | 37.04 km/h |
| 25 kn | 46.3 km/h |
| 50 kn | 92.5999 km/h |
| 100 kn | 185.1998 km/h |
| 250 kn | 462.9996 km/h |
| 500 kn | 925.9992 km/h |
| 1,000 kn | 1,852 km/h |
Common questions
Is kn to km/h 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 Kilometres per hour to Knots converter.
Mistakes to avoid
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.
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.
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.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For any value, use the Knots to Kilometres per hour Converter or browse all speed converters.
Run your own numbers: Knots to Kilometres per hour Converter