Beaufort Scale To km/h Converter
Convert Beaufort wind force numbers to kilometre-per-hour ranges, with knots, mph, m/s, land effects and marine forecast notes.
Choose A Beaufort Force
Converted Wind Speed
Choose a Beaufort force to see the km/h range.
Wind Note
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Quick Beaufort To km/h Answer
The Beaufort scale gives wind force as a numbered band, not one exact speed. Force 5 is a fresh breeze, usually shown as 29 to 38 km/h. Force 7 is near gale, around 50 to 61 km/h. Force 10 is storm, around 89 to 102 km/h. Force 12 begins at about 118 km/h and is described as hurricane force on the Beaufort scale.
The converter keeps the band structure because that is how the scale is used in Met Office marine forecasts and many weather references. A midpoint can be useful for a spreadsheet, but it should not be treated as a measured wind speed. For safety decisions, use the latest official forecast, warnings and local exposure rather than a converted number alone.
How The Conversion Works
Beaufort force 0 to 12 maps to a wind speed range
km/h values are rounded forecast bands, not exact measured speeds
mph = km/h x 0.621371
knots = km/h x 0.539957
The Beaufort scale was built around observed wind effects, especially at sea. Modern references give speed bands in knots, mph, km/h or m/s. This page starts from the commonly used km/h bands and converts the same lower and upper limits into other units. Force 12 has no upper limit in the basic 0 to 12 scale, so the converter shows 118 km/h and above rather than a closed range.
Reading A Beaufort Forecast
Force Is A Band
Beaufort 6 is not one speed; it covers a strong breeze range.
Gusts Can Be Higher
Forecast mean wind and gusts are different. A Beaufort band may not show the strongest gust.
Exposure Matters
Hills, sea fronts, bridges, open fields and high buildings can make conditions worse locally.
For walking, cycling, sailing or event planning, the same Beaufort number can feel very different depending on terrain and direction. A following wind on a sheltered cycle route is not the same as a side wind on a bridge. A marina, cliff path or open sports field may need a more cautious reading than a sheltered garden. Treat the converter as a unit aid and check official warnings before plans that depend on wind.
Beaufort Scale To km/h Table
| Force | Description | km/h | Typical Land Clue | Planning Note |
|---|---|---|---|---|
| 0 | Calm | 0 to 1 | Smoke rises vertically. | Very light air movement. |
| 1 | Light air | 1 to 5 | Smoke drift shows direction. | Almost calm for most outdoor plans. |
| 2 | Light breeze | 6 to 11 | Leaves rustle. | Comfortable for most uses. |
| 3 | Gentle breeze | 12 to 19 | Light flags extend. | Noticeable on bikes and water. |
| 4 | Moderate breeze | 20 to 28 | Dust and loose paper move. | Check gazebos and light displays. |
| 5 | Fresh breeze | 29 to 38 | Small trees sway. | Unpleasant for exposed picnics. |
| 6 | Strong breeze | 39 to 49 | Large branches move. | Difficult umbrellas and exposed cycling. |
| 7 | Near gale | 50 to 61 | Whole trees move. | Review outdoor events and coast plans. |
| 8 | Gale | 62 to 74 | Twigs may break. | Use official warnings and local advice. |
| 9 | Strong gale | 75 to 88 | Minor structural damage possible. | Avoid exposed routes where possible. |
| 10 | Storm | 89 to 102 | Trees can be damaged. | High-risk outdoor conditions. |
| 11 | Violent storm | 103 to 117 | Widespread damage possible. | Follow official warnings closely. |
| 12 | Hurricane force | 118+ | Severe damage possible. | Do not rely on a converter for safety. |
Where km/h Helps
Many UK users see wind speed in mph, while European weather apps, outdoor watches and some transport information may show km/h. A Beaufort-to-km/h conversion helps when a marine forecast says Force 6 but a walking group or sports organiser wants a metric speed. It is also useful when comparing overseas forecasts with UK coastal wording.
For marine use, knots remain important. The result panel shows knots as well because Met Office and shipping forecasts often use nautical terms. If a passage plan, harbour notice or club rule gives a knot limit, use the knot value or the original official forecast rather than converting back and forth.
Related Wind Speed Conversions
| Conversion | Factor Or Rule | Best Use |
|---|---|---|
| km/h to mph | multiply by 0.621371 | UK road-style wind comparisons. |
| km/h to knots | multiply by 0.539957 | Marine and aviation wind speeds. |
| km/h to m/s | divide by 3.6 | Engineering and meteorology. |
| knots to km/h | multiply by 1.852 | Shipping forecasts to metric speed. |
| mph to km/h | multiply by 1.609344 | Weather apps and travel planning. |
| m/s to km/h | multiply by 3.6 | Scientific readings. |
| Force 5 to km/h | 29 to 38 km/h | Fresh breeze planning. |
| Force 8 to km/h | 62 to 74 km/h | Gale warning context. |
| Force 10 to km/h | 89 to 102 km/h | Storm context. |
| Force 12 to km/h | 118 km/h and above | Hurricane-force wording. |
FAQs
How many km/h is Beaufort Force 5?
Force 5, fresh breeze, is about 29 to 38 km/h. It is a band, not one exact speed. The midpoint is about 33.5 km/h, but the range is better for reading forecasts.
What Beaufort force is 50 km/h?
Fifty km/h sits at the lower edge of Force 7, near gale. It is strong enough to make exposed walking, cycling and temporary outdoor equipment more difficult. Gusts may be higher than the mean speed.
Why is Force 12 written as 118 km/h and above?
The basic Beaufort scale stops at Force 12 for hurricane-force winds, so there is no closed upper range in the common 0 to 12 table. Some extended scales exist, but public forecasts usually use Force 12 as the top category.
Can I use Beaufort force for gusts?
Beaufort bands are usually linked to mean wind speed and observed effects. Gusts can be much higher. If an activity is sensitive to sudden gusts, read the gust forecast as well as the Beaufort or mean wind speed.
Is the Beaufort scale used only at sea?
It started with maritime observation and remains important in marine forecasts, but land effects are also used in many tables. Trees, flags, loose paper and walking difficulty can help people picture the force.
Should I cancel an event based on this converter?
No. Use it to read the unit range, then check the latest Met Office warnings, venue rules, insurer requirements and local exposure. Temporary structures and coastal sites need particular caution.
Sources
- Met Office. (n.d.). Beaufort Wind Force Scale. Met Office. https://weather.metoffice.gov.uk/guides/coast-and-sea/beaufort-scale
- Royal Meteorological Society. (n.d.). The Beaufort Wind Scale. Royal Meteorological Society. https://www.rmets.org/resource/beaufort-scale
- National Weather Service. (n.d.). Beaufort Scale. National Oceanic and Atmospheric Administration. https://www.weather.gov/crp/BeaufortScale
- Bureau International des Poids et Mesures. (2019). The International System of Units (SI), 9th edition. BIPM. https://www.bipm.org/en/publications/si-brochure