Units & Conversion · 节与公里每小时（Knot & km/h） · Updated 2026-10-25
What Is Knot & km/h?
Definition
A knot is one nautical mile per hour, the mile defined as one minute of latitude = 1,852 m. It originates from the log-line: knots tied at fixed intervals, counted against a sandglass. Because the nautical mile maps to latitude minutes, chart work reads speed×time directly as chart distance — the very reason aviation and shipping never switched to km/h. Airliners cruise at 450-480 kn ≈ 830-890 km/h.
Formula
1 kn = 1.852 km/h; 1 nmi = 1,852 m = 1 minute of latitude
Worked Example
A 350 km/h bullet train runs ~189 kn; a cruise ship at 22 kn ≈ 40.7 km/h; a typhoon reported at 44 kn blows 81 km/h.
Common Misconception
"A knot is km/h" — it is 85% more. And a nautical mile (1,852 m) is not a statute mile (1,609 m); mixing them skews distance estimates 15%. Always confirm the unit on marine and aviation bulletins.
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