Beaufort Wind Force Calculator
Convert wind speed into Beaufort wind force and see the corresponding wind description, speed ranges, and typical sea or surface conditions.
Beaufort Wind Results
What is the Beaufort wind scale?
The Beaufort scale is a standardized scale used to describe wind force using observed or measured wind speed and its visible effects on the sea or land. It ranges from Force 0, calm, to Force 12, hurricane force.
The scale is especially useful in marine weather because sailors can relate a numerical wind speed to familiar descriptions of sea conditions.
How does the Beaufort wind calculator work?
The calculator first converts the entered wind speed into knots. It then compares that speed against the standard Beaufort wind speed ranges and assigns the corresponding force.
Wind Speed → Beaufort Force → Wind Description
The result is based on the wind-speed range associated with each Beaufort force.
Beaufort wind force scale
| Force | Description | Knots | m/s | Typical Description |
|---|---|---|---|---|
| 0 | Calm | Less than 1 | Less than 0.3 | Calm conditions; smoke rises vertically. |
| 1 | Light air | 1–3 | 0.3–1.5 | Direction shown by smoke drift. |
| 2 | Light breeze | 4–6 | 1.6–3.3 | Leaves rustle; small wavelets form. |
| 3 | Gentle breeze | 7–10 | 3.4–5.4 | Leaves and small branches move. |
| 4 | Moderate breeze | 11–16 | 5.5–7.9 | Small waves become longer. |
| 5 | Fresh breeze | 17–21 | 8.0–10.7 | Moderate waves with some spray. |
| 6 | Strong breeze | 22–27 | 10.8–13.8 | Large waves with whitecaps. |
| 7 | Near gale | 28–33 | 13.9–17.1 | Sea heaps up; increasing foam. |
| 8 | Gale | 34–40 | 17.2–20.7 | Moderately high waves and spray. |
| 9 | Strong gale | 41–47 | 20.8–24.4 | High waves and dense spray. |
| 10 | Storm | 48–55 | 24.5–28.4 | Very high waves and reduced visibility. |
| 11 | Violent storm | 56–63 | 28.5–32.6 | Exceptionally high waves. |
| 12 | Hurricane force | 64+ | 32.7+ | Exceptionally destructive sea conditions. |
What is Beaufort Force 6?
Beaufort Force 6 is described as a strong breeze. It corresponds approximately to 22–27 knots of wind. On the water, large waves and widespread whitecaps are expected.
What is Beaufort Force 8?
Beaufort Force 8 is a gale, corresponding approximately to 34–40 knots. At sea, waves become moderately high and conditions can become hazardous for smaller vessels.
What is Beaufort Force 12?
Beaufort Force 12 is hurricane force and corresponds to wind speeds of 64 knots or more. It represents extremely dangerous conditions at sea and on land.
Can Beaufort force be calculated from wind speed?
Yes. Beaufort force can be determined from wind speed using the standard wind-speed ranges for the scale. This makes it possible to convert weather forecasts, anemometer readings, or marine observations into a Beaufort number.
Why is the Beaufort scale useful for sailors?
Sailors often use Beaufort force as a quick way to communicate the general strength and character of the wind. It can also provide useful context when reading sailing forecasts, marine weather reports, pilot guides, and sailing instructions.
Is Beaufort wind force the same as wind speed?
No. Wind speed is a measured physical quantity, while Beaufort force is a categorized scale. Several different wind speeds can fall within the same Beaufort force range.