Knots to KM/H Converter
Convert knots to kilometres per hour — one knot is 1.852 km/h, one nautical mile an hour. Results update as you type; exact factors shown.
One knot is 1.852 kilometres per hour — see the exact factor, not a rounded rule of thumb.
How the knots to km/h converter works
Speeds convert through metres per second. 1 km/h is 1000/3600 m/s; 1 mph is 1609.344/3600 m/s; a knot is one nautical mile (1,852 m) per hour. Mach is shown against the standard sea-level speed of sound of 340.29 m/s and varies with altitude and temperature.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common speed conversions
| From | To | Units |
|---|---|---|
| 1 kn | 1.852 km/h | knot to kilometres per hour |
| 5 kn | 9.26 km/h | knots to kilometres per hour |
| 10 kn | 18.52 km/h | knots to kilometres per hour |
| 15 kn | 27.78 km/h | knots to kilometres per hour |
| 20 kn | 37.04 km/h | knots to kilometres per hour |
| 25 kn | 46.3 km/h | knots to kilometres per hour |
| 30 kn | 55.56 km/h | knots to kilometres per hour |
| 40 kn | 74.08 km/h | knots to kilometres per hour |
| 50 kn | 92.6 km/h | knots to kilometres per hour |
| 60 kn | 111.12 km/h | knots to kilometres per hour |
| 100 kn | 185.2 km/h | knots to kilometres per hour |
| 500 kn | 926 km/h | knots to kilometres per hour |
Units in this converter and their exact factors
| Unit | Symbol | One unit in metre per seconds |
|---|---|---|
| metre per second | m/s | 1 metre per second |
| kilometre per hour | km/h | 0.2777777778 metre per second |
| mile per hour | mph | 0.44704 metre per second |
| knot | kn | 0.5144444444 metre per second |
| foot per second | ft/s | 0.3048 metre per second |
| Mach (sea level, 15 °C) | Ma | 340.29 metre per second |
FAQFrequently asked questions about speed conversion
What is a knot?
One nautical mile per hour, which is 1.852 km/h exactly.
Why is a nautical mile different?
It is one minute of latitude, so it maps directly onto a chart — which is why ships and aircraft use it.
What is 20 knots in km/h?
37 km/h.
Where did the name come from?
Sailors counted knots in a rope paid out behind the ship over a timed interval.
Do aircraft use knots too?
Yes, along with nautical miles, for the same charting reason.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.