Beaufort Scale Calculator
Calculate Beaufort wind force scale number from wind speed. Get detailed information about sea conditions, land observations, and wave heights for any wind speed measurement.
Wind Speed Input
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About Beaufort Scale
What is the Beaufort Scale?
The Beaufort Scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Developed in 1805 by Sir Francis Beaufort, a British Royal Navy officer, it provides a standardized method for estimating wind speeds based on visual observations.
Historical Background
Originally designed for sailors to estimate winds using observations of sea conditions, the Beaufort Scale has been adapted for use on land. It ranges from 0 (calm) to 12 (hurricane-force winds). The scale has been updated several times to correlate with actual measured wind speeds and extended to include higher forces.
Why It Matters
The Beaufort Scale remains widely used in weather forecasts, marine forecasts, and aviation. It provides an intuitive way to communicate wind conditions without requiring precise measurements, making it valuable for sailors, meteorologists, and the general public.
How to Use This Calculator
Our Beaufort Scale Calculator converts measured wind speeds into Beaufort numbers with detailed condition descriptions.
Step-by-Step Instructions
- Enter the wind speed value in the input field
- Select your preferred unit (m/s, km/h, mph, or knots)
- Click 'Calculate Beaufort Scale' to get results
- Review the Beaufort number, description, and condition details
- Export results to CSV or share them as needed
Applications of Beaufort Scale
The Beaufort Scale is used across various fields and industries:
Marine Navigation
Sailors and ship captains use the Beaufort Scale to assess sailing conditions, plan routes, and ensure safety at sea.
Weather Forecasting
Meteorologists incorporate Beaufort numbers in public forecasts to communicate wind conditions in an easily understandable format.
Aviation
Pilots reference the Beaufort Scale for flight planning and understanding surface wind conditions at airports.
Outdoor Activities
Hikers, campers, and outdoor enthusiasts use the scale to gauge suitable conditions for activities and assess potential hazards.
Emergency Management
Emergency services use Beaufort ratings to prepare for severe weather events and communicate risk levels to the public.
Complete Beaufort Scale Reference
The following table provides a comprehensive reference for all Beaufort numbers with corresponding wind speeds and wave heights:
| Beaufort # | Description | Wind Speed (m/s) | Wave Height (m) |
|---|---|---|---|
| 0 | Calm | 0-0.2 | 0 |
| 1 | Light Air | 0.3-1.5 | 0-0.1 |
| 2 | Light Breeze | 1.6-3.3 | 0.1-0.5 |
| 3 | Gentle Breeze | 3.4-5.4 | 0.5-1.0 |
| 4 | Moderate Breeze | 5.5-7.9 | 1.0-2.0 |
| 5 | Fresh Breeze | 8.0-10.7 | 2.0-3.0 |
| 6 | Strong Breeze | 10.8-13.8 | 3.0-4.0 |
| 7 | Near Gale | 13.9-17.1 | 4.0-5.5 |
| 8 | Gale | 17.2-20.7 | 5.5-7.5 |
| 9 | Strong Gale | 20.8-24.4 | 7.0-10.0 |
| 10 | Storm | 24.5-28.4 | 9.0-12.5 |
| 11 | Violent Storm | 28.5-32.6 | 11.5-16.0 |
| 12 | Hurricane Force | 32.7+ | 14.0+ |
Best Practices for Using the Beaufort Scale
Follow these guidelines for accurate wind assessment and safe decision-making:
- Always use measured wind speeds when available for greater accuracy
- Consider local terrain and obstacles that may affect wind patterns
- Remember that Beaufort observations are typically taken at 10 meters above ground level
- Use multiple indicators (visual, auditory, tactile) when estimating Beaufort numbers without instruments
- Be aware that sea state may lag behind wind changes, especially when winds are increasing
- Consult official weather forecasts for severe weather warnings
- Consider gustiness in addition to sustained wind speed for safety planning
Frequently Asked Questions
What is the difference between Beaufort Scale and actual wind speed?
The Beaufort Scale is a qualitative scale based on observations, while wind speed is a quantitative measurement. This calculator bridges the two by converting precise measurements into Beaufort numbers with condition descriptions.
How accurate is the Beaufort Scale?
When used by trained observers, the Beaufort Scale can estimate wind speeds within about 10-15% accuracy. However, actual anemometer measurements are always more precise.
Why does the scale only go to 12?
Originally, 12 was considered the maximum practical level for sailing ships. While extended scales exist (up to 17), the 0-12 range covers most practical applications and is universally recognized.
Can I use the Beaufort Scale on land?
Yes! While originally designed for sea conditions, the scale has been adapted with land-based observations such as tree movement, smoke behavior, and structural effects.
What Beaufort number is considered dangerous?
Beaufort 7 (Near Gale) and above are generally considered dangerous for small craft. Beaufort 10+ (Storm and above) poses significant risks to all vessels and land structures.
How do I estimate Beaufort number without instruments?
Observe visual indicators: flag movement, tree motion, wave formation, smoke drift, etc. Compare your observations with the descriptions in the Scale Reference table above.