Knots to KM/H Converter
Convert knots to kilometers 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 kilometer per hour — see the exact factor, not a rounded rule of thumb.
How the knots to km/h converter works
Speeds convert through meters 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 US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common speed conversions
| From | To | Units |
|---|---|---|
| 1 kn | 1.852 km/h | knot to kilometer per hour |
| 5 kn | 9.26 km/h | knots to kilometer per hour |
| 10 kn | 18.52 km/h | knots to kilometer per hour |
| 15 kn | 27.78 km/h | knots to kilometer per hour |
| 20 kn | 37.04 km/h | knots to kilometer per hour |
| 25 kn | 46.3 km/h | knots to kilometer per hour |
| 30 kn | 55.56 km/h | knots to kilometer per hour |
| 40 kn | 74.08 km/h | knots to kilometer per hour |
| 50 kn | 92.6 km/h | knots to kilometer per hour |
| 60 kn | 111.12 km/h | knots to kilometer per hour |
| 100 kn | 185.2 km/h | knots to kilometer per hour |
| 500 kn | 926 km/h | knots to kilometer per hour |
Units in this converter and their exact factors
| Unit | Symbol | One unit in meter per seconds |
|---|---|---|
| meter per second | m/s | 1 meter per second |
| kilometer per hour | km/h | 0.2777777778 meter per second |
| mile per hour | mph | 0.44704 meter per second |
| knot | kn | 0.5144444444 meter per second |
| foot per second | ft/s | 0.3048 meter per second |
| Mach (sea level, 15 °C) | Ma | 340.29 meter 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 Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.