Beaufort Scale and Probable Wave Height

 
Beaufort
number
Description term Wind speeds Wave height (m)
Wind Wave knots m/s probable maximum
0 Calm - < 1 0 - 0.2 - -
1 Light air Ripples 1 - 3 0.3 - 1.5 0.1 0.1
2 Light breeze Small wavelets 4 - 6 1.6 - 3.3 0.2 0.3
3 Gentle breeze Large wavelets 7 - 10 3.4 - 5.4 0.6 1.0
4 Moderate breeze Small waves 11 - 16 5.5 - 7.9 1.0 1.5
5 Fresh breeze Moderate waves 17 - 21 8.0 - 10.7 2.0 2.5
6 Strong breeze Large waves 22 - 27 10.8 - 13.8 3.0 4.0
7 Near gale Large waves 28 - 33 13.9 - 17.1 4.0 5.5
8 Gale Moderately high waves 34 - 40 17.2 - 20.7 6.0 7.5
9 Strong gale High waves 41 - 47 20.8 - 24.4 7.0 10.0
10 Storm Very high waves 48 - 55 24.5 - 28.4 9.0 12.5
11 Violent storm Exceptionally high waves 56 - 63 28.5 - 32.6 11.5 16.0
12 Hurricane Exceptionally high waves 64 - 71 32.7 - 36.9 14.0 > 16
13 Hurricane Exceptionally high waves 72 - 80 37.0 - 41.4 > 14 > 16
14 Hurricane Exceptionally high waves 81 - 89 41.5 - 46.1 > 14 > 16
15 Hurricane Exceptionally high waves 90 - 99 46.2 - 50.9 > 14 > 16
16 Hurricane Exceptionally high waves 100 - 109 51.0 - 56.0 > 14 > 16
17 Hurricane Exceptionally high waves 109 - 118 56.1 - 61.2 > 14 > 16