How do you convert knots to kilometres per hour?

Multiply the speed in knots by 1.852 to get kilometres per hour. This conversion factor is exact: 1 knot is defined as exactly 1.852 km/h (or one nautical mile per hour, where one nautical mile is exactly 1,852 metres). For example, 20 knots = 20 x 1.852 = 37.04 km/h.

What is a knot and why is it used?

A knot is a unit of speed equal to one nautical mile per hour. One nautical mile is 1,852 metres, which corresponds to one minute of arc of latitude on the Earth's surface. Knots are used internationally in maritime navigation, aviation, and meteorology because the relationship between distance (nautical miles) and latitude makes position plotting straightforward. Wind speeds in weather forecasts are also commonly given in knots.

How fast is 30 knots in kph?

30 knots equals 55.56 km/h (30 x 1.852 = 55.56). In context, 30 knots is a fast sailing or motorboat speed, roughly equivalent to 34.5 mph. Gale-force winds are typically defined as beginning at about 34 knots (63 km/h) on the Beaufort scale.

Knots to KPH Converter

Convert knots to kilometres per hour (km/h), miles per hour (mph), and metres per second (m/s). The conversion is exact: 1 knot = 1.852 km/h. Also includes a reverse kph-to-knots converter and a reference table of common speeds.

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Exact conversion 1 knot = 1.852 km/h exactly (SI / BIPM definition, adopted internationally).

1. Knots to KPH

Speed in knots

Decimal places

2. KPH to Knots (Reverse)

Speed in km/h

km/h

Enter a value in either field. The other will update automatically.

Conversion Results

Kilometres per hour
37.04
km/h

Miles per hour

23.02

mph

Metres per second

10.29

m/s

Feet per second

33.76

ft/s

Conversion Breakdown

Input speed20 knots

Conversion factor1 kn = 1.852 km/h

Kilometres per hour37.04 km/h

Miles per hour23.02 mph

Metres per second10.29 m/s

Feet per second33.76 ft/s

Context: What This Speed Looks Like

Beaufort scaleForce 5 (Fresh breeze)

Typical contextStrong sailing wind

Knots per km/h0.540 kn per km/h

Nautical miles/hr20.00 nm/h (same as knots)

Common Speed Reference Table

Knots	km/h	mph	m/s	Typical context

How to Convert Knots to KPH

To convert knots to kilometres per hour, multiply the speed in knots by 1.852. This factor is exact, not approximate: one knot is defined as exactly one nautical mile per hour, and one nautical mile is defined as exactly 1,852 metres. Therefore:

km/h = knots x 1.852

To convert back from km/h to knots, divide by 1.852 (or multiply by 0.53996).

Worked example: Convert 20 knots to km/h.
20 x 1.852 = 37.04 km/h
20 x 1.852 / 1.60934 = 23.02 mph
20 x 1.852 / 3.6 = 10.29 m/s

Why Are Speeds Measured in Knots?

Knots are used in maritime and aviation contexts because of their direct relationship to the Earth's coordinate system. One nautical mile equals one minute of arc (1/60 of a degree) of latitude. This means that if you travel one nautical mile, you have moved exactly 1/60 of a degree of latitude, making navigation calculations much simpler on a chart. A ship travelling at 10 knots for one hour covers exactly 10 nautical miles, which corresponds to a predictable angular change in latitude.

Weather services worldwide, including MetService in New Zealand, commonly report wind speeds in knots. Aviation uses knots for airspeed, ground speed, and wind speed. Maritime vessel speeds are almost universally quoted in knots.

Other Useful Conversions

From knots to...	Multiply by	Example (1 knot)
Kilometres per hour (km/h)	1.852	1.852 km/h
Miles per hour (mph)	1.15078	1.151 mph
Metres per second (m/s)	0.51444	0.514 m/s
Feet per second (ft/s)	1.68781	1.688 ft/s
Feet per minute (ft/min)	101.269	101.3 ft/min

The Beaufort Wind Scale in Knots and KPH

The Beaufort scale is an empirical measure of wind speed widely used in maritime and aviation weather. It was originally devised by Admiral Francis Beaufort in 1806 and describes wind conditions from Force 0 (calm) to Force 12 (hurricane). Weather forecasts in New Zealand often use Beaufort descriptions alongside wind speeds in knots or km/h.

Beaufort	Description	Knots	km/h
0	Calm	<1	<2
1	Light air	1 to 3	2 to 6
2	Light breeze	4 to 6	7 to 11
3	Gentle breeze	7 to 10	12 to 19
4	Moderate breeze	11 to 16	20 to 30
5	Fresh breeze	17 to 21	31 to 39
6	Strong breeze	22 to 27	40 to 50
7	Near gale	28 to 33	51 to 62
8	Gale	34 to 40	63 to 74
9	Strong gale	41 to 47	75 to 88
10	Storm	48 to 55	89 to 102
11	Violent storm	56 to 63	103 to 117
12	Hurricane	64+	119+

Related Calculators

Essential Calculators: the full collection of converters and tools.
Speed Converter: convert between km/h, mph, m/s, and more.
KM to Miles Converter: convert kilometres to miles.
Crosswind Calculator: calculate crosswind and headwind components from wind speed and direction.
Speed Calculator: calculate speed, distance, or time from the other two values.

Sources and method: The conversion factor 1 knot = 1.852 km/h is exact under the International System of Units (SI) as published by the Bureau International des Poids et Mesures (BIPM). One nautical mile = 1,852 metres exactly, as defined by the International Hydrographic Organization. The Beaufort scale descriptions and speed ranges follow the World Meteorological Organization (WMO) specification.

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