Wind Speed Converter (Knots · mph · km/h · m/s · Beaufort)

Because the nautical mile is one minute of latitude: a ship logging 12 knots covers 12 minutes of arc per hour, so speed, chart distance and position arithmetic share one unit system with no conversion. The same logic carried into aviation — airways, ATC and METARs are all knot-denominated. 'Knot' itself is literal: log lines were knotted every 47 ft 3 in and counted against a 28-second sandglass, hand-measuring arc-minutes per hour.

The landlubber calibration: F2 leaves rustle, F4 dust lifts and small branches move, F6 umbrellas struggle and wires whistle, F8 twigs break and walking leans, F10 trees uproot and structural damage begins, F12 (64+ kt) is hurricane force. The scale's genius is observability — a forecast of 'F6' is verifiable by anyone with eyes, which is why marine forecasts (UK Shipping Forecast most famously) never abandoned it.

Sustained averages with gusts reported separately: WMO/aviation convention is a 10-minute mean at 10 m height (US surface obs use 2 minutes), with 'G' values for the peak 3-second gust. Gusts typically run 30–60% over the sustained speed near the surface, more in rough terrain. Wind-load engineering, by contrast, designs against 3-second gusts entirely — so a building code '90 mph wind' and a forecast '90 mph sustained' are very different storms.

Pressure grows with speed SQUARED: q = ½ρV², so doubling wind quadruples load — a 40-kt gust pushes four times harder than a 20-kt breeze, and F10 carries ~9× the force of F6. This is why the Beaufort scale's damage descriptions escalate so fast in its upper third, why tents fail suddenly rather than gradually, and why our crane and scaffold wind-limit tools (and every building code) work in dynamic pressure rather than raw speed.