Convert Beaufort Scale to Kilometer per Hour (Bft → km/h)
The Beaufort scale rates wind force from 0 (calm) to 12 (hurricane), used by sailors and meteorologists.
Beaufort Scale to Kilometer per Hour Conversion Table
10 common values| Beaufort Scale | Kilometer per Hour |
|---|---|
| 1 Bft | 3.6 km/h |
| 5 Bft | 18 km/h |
| 10 Bft | 36 km/h |
| 25 Bft | 89.999999 km/h |
| 50 Bft | 180 km/h |
| 100 Bft | 360 km/h |
| 150 Bft | 540 km/h |
| 200 Bft | 719.99999 km/h |
| 300 Bft | 1,080 km/h |
| 500 Bft | 1,800 km/h |
How to Convert Beaufort Scale to Kilometer per Hour Manually
Step by StepConverting Beaufort to kilometers per hour is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in BeaufortStart with the number of Beaufort (Bft) you want to convert.
- 2Multiply by 3.6The conversion factor from Bft to km/h is 3.6. Multiply your value by this number.
- 3Read the result in kilometers per hourThe result is your value in kilometers per hour (km/h).
Formula
Multiply the value in Beaufort by 3.6. For the reverse direction, multiply by 0.277778.
m/s = 0.836 × Bft^1.5Bft = (m/s ÷ 0.836)^(1/1.5)Tips
Use these in everyday conversions- Beaufort is empirical — conversion to m/s uses v = 0.836 × B^1.5.
- Force 4 (moderate breeze) = 5.5–7.9 m/s.
- Marine forecasts still use Beaufort alongside knots.
Common Mistakes
Avoid these- Treating Beaufort as a linear scale — it is a power relationship.
- Converting Beaufort to km/h by multiplying — always use the empirical formula.
- Using Beaufort for land winds — it was designed for sea conditions.
About Beaufort Scale and Kilometer per Hour
What is the Beaufort Scale?
The Beaufort scale is an empirical wind-force scale ranging from 0 (calm) to 12 (hurricane), developed in 1805 by British Royal Navy Admiral Francis Beaufort. Originally designed for ships at sea, the scale was based on observed effects: 'How much sail can my ship safely carry?' Modern versions describe both observed effects on land and sea and corresponding wind-speed ranges. Force 0 is dead calm (under 1 km/h), Force 6 is 'strong breeze' (39–49 km/h, large branches in motion), Force 10 is a 'whole storm' (89–102 km/h), and Force 12 is hurricane (over 118 km/h). The conversion to numeric speeds follows v = 0.836 × Bft^1.5 m/s. Sailors, meteorologists, and shipping forecasts still use the Beaufort scale because its descriptive nature is intuitive: 'Force 8 gale' immediately conveys conditions to anyone familiar with the scale.
- Marine weather forecasts
- Sailing and offshore navigation
- Historical weather records
Force 5 (fresh breeze): 17–21 knots, white-caps form. Force 8 (gale): 34–40 knots. Force 12: 64+ knots.
What is the Kilometer per Hour?
Kilometers per hour is the universal road-speed and weather wind-speed unit in 195 countries — every nation outside the United States, the United Kingdom, and a handful of Caribbean territories. Speed limits on European, Asian, Australian, African, and Latin American roads are posted in km/h: typical urban limits are 50 km/h, highway 100–130 km/h. Weather reports give wind speeds in km/h universally. The unit derives directly from the kilometer (distance) and hour (time): 1 km/h ≈ 0.278 m/s. Car speedometers in metric countries display km/h prominently, with smaller mph numbers for travel to the UK. Olympic 100-meter sprints reach 36–37 km/h, urban cyclists travel at 15–25 km/h, and commercial trains in Europe cruise at 200–300 km/h. The unit relates to mph (1 km/h ≈ 0.621 mph), m/s (3.6 km/h = 1 m/s), and the knot (1 km/h ≈ 0.540 kn).
- European and global road speed limits
- Car and motorcycle speedometers
- Weather wind speed reporting (in some regions)
German Autobahn typical speed: 130 km/h (recommended) to 180+ (no limit sections). French limit: 130 km/h. Urban: 50 km/h.