Convert a wind speed to its Beaufort force number and description.
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How do you convert wind speed to a Beaufort scale number?
The Beaufort scale relates a wind speed to its force number (0 to 12), name and conditions, from calm to hurricane force. Enter a speed in km/h, mph, m/s or knots to get the matching force. For example, 25 km/h (about 6.9 m/s) is Beaufort force 4, a "moderate breeze" — handy when you have no anemometer reading.
Understanding your result
The Beaufort scale relates wind speed to observable effects on land and sea, which is handy when you don’t have an anemometer reading.
Worked example
25 km/h (about 6.9 m/s) is Beaufort force 4, a “moderate breeze”.
How to use this tool
- Enter the wind speed.
- Choose the unit (km/h, mph, m/s or knots).
- Press Calculate.
About the Beaufort Wind Scale Calculator
The Beaufort Wind Scale Calculator turns a wind speed into its Beaufort force (0–12) with the name and the conditions you’d expect, from calm to hurricane force.
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Frequently asked questions
What is hurricane force on the Beaufort scale?
Force 12 — winds of 32.7 m/s (about 118 km/h) or more, causing severe, devastating damage.