Beaufort Scale Converter
Convert any wind speed to its Beaufort force number, name, and observed effects.
The Beaufort wind scale was devised by Royal Navy Admiral Francis Beaufort in 1805 as a standardised way to describe wind conditions by their observable effects on the sea and on land. It ranges from Force 0 (calm, smoke rises vertically) to Force 12 (hurricane-force winds with widespread structural damage). The World Meteorological Organisation (WMO) defines each Beaufort number by a specific range of wind speed in metres per second.
Enter a wind speed in either m/s or km/h and the tool will identify the corresponding Beaufort force, its official name, a description of observable effects, and conversions to m/s, km/h, and mph. The Beaufort scale is widely used in marine weather forecasts and is a useful reference for wind turbine operators assessing site conditions.
Beaufort scale result
Standard Beaufort scale thresholds (m/s). Developed by Admiral Francis Beaufort in 1805 and still used in marine and meteorological contexts worldwide.
How to use this tool
- Enter a wind speed value in the input field.
- Select the unit — m/s or km/h — from the dropdown.
- Press Convert to see the Beaufort force, name, description, and all speed conversions.
- Use Reset to return to the default values.
💡 Good to know
All calculations use standard, published formulas and simplified assumptions so beginners can build intuition. For real projects, always consult qualified engineers and site-specific data.
Frequently asked questions
What is Beaufort Force 12?
Force 12 is hurricane-force wind, defined as 32.7 m/s (about 118 km/h) or above. It is associated with widespread severe structural damage. Most wind turbines cut out well before this speed — typically at 20–25 m/s — to protect their mechanical components.
Why does the Beaufort scale stop at 12?
Beaufort originally designed the scale for sailing ships. The WMO extended it to 12 to describe hurricane-force winds. Some national meteorological services use extensions beyond 12 for extreme events, but 0–12 is the internationally recognised standard.
What Beaufort force is best for wind turbines?
Turbines start generating at roughly Force 3–4 (3–8 m/s), reach rated power around Force 6–7 (11–17 m/s), and cut out at Force 9–10 (around 20–25 m/s). Optimal generation is typically in the Force 5–7 range.
How is mph calculated from m/s?
Multiply metres per second by 2.23694 to get miles per hour. For example, 10 m/s × 2.23694 = 22.4 mph.