Wind Speed Calculator
Convert between wind speed units and determine Beaufort scale measurements for meteorological applications.
Wind Speed Conversion Results
Miles per hour (mph):
Kilometers per hour (km/h):
Knots (kn):
Meters per second (m/s):
Feet per second (ft/s):
Beaufort scale (Bft):
Beaufort Scale Description
About Our Wind Speed Calculator
Our Wind Speed Calculator is a comprehensive tool for converting between different wind speed units and understanding the Beaufort scale. Whether you're a meteorologist, sailor, pilot, or weather enthusiast, this calculator simplifies the process of interpreting wind measurements across various systems.
Wind Speed Units Explained
Wind speed can be measured in several different units depending on the context and country. Here are the most common units:
- Miles per hour (mph) - Common in the US and UK for weather forecasts
- Kilometers per hour (km/h) - Standard in most countries using the metric system
- Knots (kn) - Used in navigation, aviation, and marine forecasts (1 knot = 1 nautical mile per hour)
- Meters per second (m/s) - The SI unit, used in scientific contexts
- Feet per second (ft/s) - Sometimes used in engineering applications
Understanding the Beaufort Scale
The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Developed in 1805 by Sir Francis Beaufort, it ranges from 0 (calm) to 12 (hurricane force) and provides a quick way to estimate wind speeds without instruments.
| Beaufort Number | Description | Wind Speed (mph) | Visible Effects |
|---|---|---|---|
| 0 | Calm | < 1 | Smoke rises vertically |
| 1 | Light air | 1-3 | Smoke drift indicates wind direction |
| 2 | Light breeze | 4-7 | Wind felt on face, leaves rustle |
| 3 | Gentle breeze | 8-12 | Leaves and small twigs in constant motion |
| 4 | Moderate breeze | 13-18 | Raises dust and loose paper |
| 5 | Fresh breeze | 19-24 | Small trees in leaf begin to sway |
| 6 | Strong breeze | 25-31 | Large branches in motion |
| 7 | Near gale | 32-38 | Whole trees in motion |
| 8 | Gale | 39-46 | Twigs break off trees |
| 9 | Strong gale | 47-54 | Slight structural damage occurs |
| 10 | Storm | 55-63 | Trees uprooted, considerable structural damage |
| 11 | Violent storm | 64-72 | Widespread damage |
| 12 | Hurricane | ≥ 73 | Catastrophic damage |
Wind Speed Conversion Formulas
Our calculator uses the following conversion formulas:
• 1 mph = 1.60934 km/h
• 1 mph = 0.868976 knots
• 1 mph = 0.44704 m/s
• 1 mph = 1.46667 ft/s
• Beaufort scale is calculated using specific wind speed ranges
Key Features:
- Convert between five different wind speed units (mph, km/h, knots, m/s, ft/s)
- Beaufort scale calculation with descriptive information
- Easy-to-use interface with instant results
- Comprehensive reference information for meteorological applications
How to Use This Calculator:
- Enter your wind speed value in the input field
- Select the unit of your input value from the dropdown
- Click "Calculate Wind Speed" to see conversions to all other units
- View the Beaufort scale description that corresponds to your wind speed
Practical Applications:
Weather Forecasting: Convert between units used in different forecasting systems.
Aviation: Pilots need to understand wind speeds in knots for flight planning.
Maritime Navigation: Sailors use the Beaufort scale and knots to assess sailing conditions.
Construction: Engineers need to understand wind loads when designing structures.
Outdoor Activities: Assess whether conditions are suitable for activities like kite flying, windsurfing, or outdoor events.
Whether you're interpreting a weather forecast, planning a sailing trip, or preparing for outdoor activities, our Wind Speed Calculator provides accurate conversions and helpful context to make wind speed measurements meaningful.
Frequently Asked Questions
Why are knots used for wind speed in aviation and marine contexts?
Knots are used in aviation and marine contexts because they directly relate to nautical miles, which are the standard unit of distance in these fields. One knot equals one nautical mile per hour. Nautical miles are based on the circumference of the Earth (1 nautical mile is 1 minute of latitude), making them particularly useful for navigation. Using knots allows for easier calculations when determining travel times and distances over the Earth's surface.
How accurate is the Beaufort scale for estimating wind speed?
The Beaufort scale provides a reasonably accurate estimation of wind speed based on observable conditions, but it's not as precise as direct measurement. It was developed before modern anemometers were widely available, allowing sailors to estimate wind speeds by observing sea conditions. On land, observations of smoke, trees, and other objects are used. While useful for quick estimates, the Beaufort scale is subjective and can vary based on the observer's interpretation of conditions. For critical applications requiring precise measurements, an anemometer should be used.
What wind speeds are considered dangerous?
Wind speeds typically become dangerous around 40-45 mph (Beaufort 8-9), when walking becomes difficult and twigs break from trees. At 55-63 mph (Beaufort 10), structural damage begins to occur. Winds over 75 mph (hurricane force, Beaufort 12) can cause severe and widespread damage to structures. Different activities have different thresholds - construction cranes may stop operating at much lower speeds (20-25 mph), while certain bridges may close to high-profile vehicles at 30-40 mph. The danger also depends on duration, terrain, and whether the wind is gusty or sustained.