What is the Beaufort scale?

The Beaufort scale is an empirical measure that relates wind speed to observed conditions. It runs from 0 (Calm — smoke rises vertically) to 12 (Hurricane force — air filled with foam and spray, visibility severely impaired). It was devised by British Admiral Francis Beaufort in 1805.

What units does the converter accept?

You can enter wind speed in kilometres per hour (km/h), metres per second (m/s), miles per hour (mph), or knots (kt). The tool converts internally to m/s before looking up the Beaufort force.

Is Force 12 the highest Beaufort level?

Yes. The original Beaufort scale tops out at Force 12 (Hurricane), defined as wind speeds above 32.7 m/s (64+ knots / 73+ mph). Some meteorological agencies extend to Force 17 for tropical cyclones, but the standard WMO scale ends at 12.

How accurate is the Beaufort scale for modern use?

The speed boundaries are well-established and universally recognised. However, actual observable conditions depend on terrain, sea state history (swell vs. fresh wind), and air density. The scale is best used as a quick communication shorthand alongside measured anemometer data.

What is the difference between land and sea descriptions?

Land descriptions focus on visible effects such as tree movement, dust, or structural damage. Sea descriptions focus on wave height and surface appearance. Both are included for each Beaufort level because conditions look very different over open water versus over land.

Beaufort Wind Scale

Enter a wind speed in any unit and instantly see the Beaufort force number plus land and sea condition descriptions.

Wind Speed Input

Wind Speed

Unit

Enter a wind speed above to see the Beaufort force.

Beaufort Scale Reference Table

All 13 force levels with speed ranges and conditions. Your current result is highlighted.

Force	Name	km/h	knots	Land description

Summary

The Beaufort Wind Scale is a 13-level empirical scale (0–12) that relates wind speed to observed conditions on land and at sea. Originally devised by Admiral Sir Francis Beaufort in 1805, it remains the standard reference used by mariners, meteorologists, and emergency services worldwide. This tool converts any wind speed into a Beaufort force number and shows the associated descriptive conditions.

How it works

Enter a wind speed value in the input field.
Select your preferred unit: km/h, m/s, mph, or knots.
The tool instantly maps the speed to the correct Beaufort force (0–12).
A full reference table below highlights your force level for easy comparison.
Switch units at any time — the result updates immediately.

Use cases

Mariners and sailors checking sea state for passage planning.
Pilots and drone operators assessing wind conditions before flight.
Meteorologists communicating wind strength to the public.
Hikers and climbers evaluating exposure risk on ridgelines.
Emergency managers describing wind severity during storm events.
Students learning weather observation and wind classification.
Journalists reporting wind conditions during weather events.
Researchers comparing historical wind records using a common scale.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu