Knots to km/h Calculator
Convert a speed in knots to kilometres per hour, miles per hour, metres per second and feet per second. The conversion is exact: 1 knot = 1 nautical mile per hour = 1.852 km/h.
kn
Exact conversion: 1 knot = 1.852 km/h
- 1
Nautical mile in metres
1 nmi = 1,852 m = 1,852International nautical mile, exact by definition. - 2
km/h per knot
1,852 ÷ 1,000 = 1.852 - 3
Convert to km/h
20 × 1.852 = 37.040
How does this calculator work?
Multiply knots by 1.852 to get km/h (exact, since 1 nautical mile = 1852 m exactly). Example: 20 kn = 37.04 km/h = 23.02 mph = 10.29 m/s. The calculator also classifies the speed on the Beaufort wind scale (0 calm → 12 hurricane).
Formula
How this is calculated
The knot (symbol kn) is a unit of speed equal to one nautical mile per hour. The nautical mile is defined as exactly 1852 metres — chosen historically to be very close to one arcminute of latitude on a meridian. Because 1 hour = 3600 s, one knot equals exactly 1852 ÷ 3600 = 0.51444... m/s, and multiplying by 3.6 gives exactly 1.852 km/h. All conversions from knots are therefore exact arithmetic derivations from this single exact equivalence.
Miles per hour (mph) follows from 1 knot = 1.852 km/h and 1 statute mile = 1.609344 km (both exact definitions), giving 1 knot = 1.852 ÷ 1.609344 ≈ 1.15078 mph. Feet per second uses 1 foot = 0.3048 m (exact international foot).
The Beaufort wind scale classification is included because knots are the standard unit for wind speed in meteorology and sailing. The scale runs from 0 (calm, < 1 kn) to 12 (hurricane force, ≥ 64 kn). The thresholds used here are the WMO (World Meteorological Organization) standard Beaufort limits.
Frequently asked questions
1 knot = 1.852 km/h exactly. This is because 1 nautical mile = 1852 m (exact), so 1 knot = 1852 m/h = 1.852 km/h.
The nautical mile was defined to match one arcminute of latitude, making navigation with charts and position fixes straightforward. Charts in aviation and maritime use are still drawn on this basis, so speeds in knots and distances in nautical miles stay compatible with navigation calculations.
Most sailing dinghies and keelboats perform well in 8–20 knots (15–37 km/h, Beaufort 3–5). Kiteboarding typically requires 12–25 knots (22–46 km/h). Below 8 knots is marginal for most wind sports.
Also known as
TG we-Calculate Editorial Team. (2026). Knots to km/h Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/knots-to-kph-calculator
TG we-Calculate Editorial Team. "Knots to km/h Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/knots-to-kph-calculator.
TG we-Calculate Editorial Team, "Knots to km/h Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/knots-to-kph-calculator
@misc{wecalculate_knots_to_kph_calculator, title = {Knots to km/h Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/knots-to-kph-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?