Beaufort Wind Scale Lookup

Beaufort 0-12: from "calm" (0 mph) to "hurricane" (>72 mph).

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Result

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How to use this calculator

  • Enter wind speed in mph.
  • Read Beaufort number + name.

About this calculator

Admiral Francis Beaufort's 1805 scale: empirical wind force from "calm" (0) to "hurricane" (12), based on observable effects on land and sea. Useful when no anemometer — you can guess Beaufort number from waves, smoke, leaves, branches. 0 calm; 4 small branches move; 7 whole trees in motion; 10 trees uprooted; 12 widespread devastation.

Frequently asked

Why does it stop at 12?+
Originally 12 covered all practical sea states. Extensions to 17 added later for tropical cyclones.
Beaufort observations?+
0: smoke rises straight. 4: small branches move. 7: whole trees motion. 10: trees uprooted. 12: widespread destruction.
Conversion to other units?+
Beaufort 4 = 11-16 mph = 17-27 km/h = 10-15 kn. Each level ~5-6 mph wider.
Hurricane category?+
Saffir-Simpson hurricane scale extends Beaufort 12+. Cat 1 = 74 mph (Beaufort 12 floor); Cat 5 = 157+ mph.
Used today?+
Marine forecasts use it. Land weather usually skips to mph/Cat. Sailors still use Beaufort frequently.

Related calculators

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1 knot = 1.15078 mph = 1.852 km/h. Bidirectional, also m/s.
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Surface gravity table for solar system bodies.
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R = F + 459.67. Rankine is absolute (0 = absolute zero); Fahrenheit + 460.
Pressure psi ↔ bar
1 bar = 14.5038 psi = 100 kPa = 0.987 atm.
Pressure bar ↔ atm
1 atm = 1.01325 bar = 14.696 psi.
Time Seconds ↔ Minutes / Hours
Convert seconds to days/hours/minutes/seconds; auto-format hh:mm:ss.

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1 knot = 1.15078 mph = 1.852 km/h. Bidirectional, also m/s.

Gravity on Other Planets
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Surface gravity table for solar system bodies.

Temperature Rankine ↔ Fahrenheit
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R = F + 459.67. Rankine is absolute (0 = absolute zero); Fahrenheit + 460.

Pressure psi ↔ bar
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1 bar = 14.5038 psi = 100 kPa = 0.987 atm.

Pressure bar ↔ atm
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1 atm = 1.01325 bar = 14.696 psi.

Time Seconds ↔ Minutes / Hours
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Convert seconds to days/hours/minutes/seconds; auto-format hh:mm:ss.