Nautical speed converter (knots)
Convert between knots, nautical miles per hour or minute, km/h, m/s, mph, ft/s, cables per hour and Mach using 1 knot = 1 nmi/h = 1.852 km/h, listing all nine nautical speed units at once.
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Conversion result
The first line is source → target; all nine units follow.
Enter a speed to convert it
Units: 0 · Converted: 0
What this tool does
- Translate a captain's knots into km/h or m/s for comparison with land speeds.
- Plan sailing or powerboat passages by converting target speeds into m/s for time estimates.
- Untangle nautical documents where nautical miles, cables and knots are mixed.
Example
Input
20
Output
节 (kn) → 英里每小时 (mph)：20 kn = 23.015589 mph 定义值：1 节 = 1 海里/小时 = 1.852 km/h = 0.514444 m/s 节 (kn) = 20 kn 海里每小时 (nmi/h) = 20 nmi/h 海里每分 (nmi/min) = 0.333333 nmi/min 千米每小时 (km/h) = 37.04 km/h 米每秒 (m/s) = 10.288889 m/s 英里每小时 (mph) = 23.015589 mph 英尺每秒 (ft/s) = 33.756197 ft/s 链每小时 (cable/h) = 200 cable/h 马赫 (Ma) = 0.030236 Ma
One knot is one nautical mile per hour, exactly 1.852 km/h, so 30 knots is 55.56 km/h.
Frequently asked questions
Why is one knot exactly 1.852 km/h?
The international nautical mile was defined as exactly 1852 m in 1929, and a knot is one nautical mile per hour, so 1 knot = 1852 m/h = 1.852 km/h — exact, not approximate.
How does a nautical mile differ from a statute mile?
A nautical mile is tied to the globe — one minute of latitude — which makes chart distance measurement easy; the statute mile is 1609.344 m. One nautical mile is about 1.150779 statute miles.
What is a cable?
A cable is a short nautical distance of 1/10 nautical mile = 185.2 m, used for anchor chain and close manoeuvring. As a speed, one cable per hour is 0.1 knot; it is listed mainly for slow-speed work.
How is Mach defined?
Mach is the multiple of local sound speed. At sea level in the standard atmosphere (15 °C) that is 340.29 m/s, so 1 Ma = 340.29 m/s. Colder air aloft lowers the sound speed, so the same indicated speed gives a higher Mach number; this tool uses the sea-level value.
How does this differ from the general speed converter?
The general converter covers metric, imperial and Mach. This one is organised around nautical practice — knots, nautical miles per minute, cables per hour — and pins the definition 1 knot = 1.852 km/h at the top of the result for hand checks.
Keywords：航速换算knots to km/h节换算海里每小时船速马赫nautical speed1.852