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Wind Speed Converter

Converter

Show all unit conversions

Show Beaufort scale

Common Wind Speed Reference

Descriptionm/sknmph
Calm000
Light breeze23.94.5
Gentle breeze47.88.9
Fresh breeze917.520.1
Near gale1529.233.6
Gale183540.3
Violent storm3058.367.1
Hurricane3568.178.3

About This Tool

Wind Speed Converter – m/s, km/h, mph, Knots, and ft/s

Wind speed is reported in different units depending on the context. Meteorologists commonly use meters per second (m/s) or kilometers per hour (km/h), while the United States typically uses miles per hour (mph). Aviation and maritime navigation rely on knots (kn), and some engineering calculations use feet per second (ft/s). This Wind Speed Converter lets you switch between all five units instantly, and optionally shows the corresponding Beaufort Wind Force Scale category so you can understand what any wind speed actually feels like.

How to Use the Wind Speed Converter

Enter a wind speed value in the input field, choose the source unit from the From Unit dropdown, and select the target unit in the To Unit dropdown. The converter updates the result immediately. Enable Show all unit conversions to see the value expressed in all five supported units at once — useful when you need to communicate wind speed to different audiences simultaneously. The Swap button reverses the conversion direction and carries over the current result as the new input.

Supported Wind Speed Units

The five units covered by this tool are the most widely used across weather science, transport, and engineering:

  • Meters per Second (m/s) — The SI unit for speed and the standard in scientific meteorology and wind energy engineering. Weather models, anemometer readings, and turbine power curves typically reference m/s.
  • Kilometers per Hour (km/h) — Commonly used in public weather forecasts across Europe, Asia, Australia, and most of the world. Easy to relate to road-traffic speeds.
  • Miles per Hour (mph) — The standard for weather reports and highway speeds in the United States and the United Kingdom. Hurricane categories in the US are defined in mph.
  • Knots (kn) — One nautical mile per hour, equal to exactly 1.852 km/h. The universal standard for aviation (METAR / TAF reports) and maritime navigation. Wind barbs on synoptic charts are measured in knots.
  • Feet per Second (ft/s) — Occasionally used in US engineering calculations, ballistics, and wind-load structural analysis where Imperial units are required.

Conversion Factors and Formulas

All conversions route through meters per second as the canonical base unit to minimise rounding errors. The key factors are:

  • 1 m/s = 3.6 km/h
  • 1 m/s = 2.23694 mph
  • 1 m/s = 1.94384 kn
  • 1 m/s = 3.28084 ft/s
  • 1 kn = 1.15078 mph (derived)

For any conversion, multiply the input value by the factor that brings it to m/s, then multiply again by the factor for the target unit. For example, to convert 25 knots to mph: 25 × 0.514444 m/s/kn ÷ 0.44704 m/s/mph ≈ 28.77 mph.

The Beaufort Wind Force Scale

Devised by British Royal Navy Admiral Sir Francis Beaufort in 1805, the Beaufort scale correlates wind speed to observable effects on the sea and land. It runs from Force 0 (Calm) — smoke rises vertically and the sea is like a mirror — up to Force 12 (Hurricane Force), where wind speed exceeds 64 knots (74 mph / 33 m/s) and causes devastating damage. The scale is still used in marine weather forecasts around the world.

This converter displays the Beaufort force number and descriptive label for any wind speed you enter. Enable the Show Beaufort scale toggle and the force category updates automatically as you type. This is particularly useful for sailors, pilots, and outdoor event planners who need to translate a numeric forecast into practical conditions on the ground or at sea.

Practical Use Cases

The Wind Speed Converter is designed for a wide range of users and situations:

  • Pilots and sailors — Convert METAR or ATIS wind readings from knots to km/h or m/s for pre-flight or voyage planning.
  • Meteorologists and students — Translate between m/s (used in global weather models) and the unit required by a local forecast format.
  • Wind energy engineers — Convert turbine site assessment data between m/s (IEC standard) and mph or km/h for client reports.
  • Outdoor event planners — Look up the Beaufort category for a forecast wind speed to assess whether conditions are suitable for tents, stages, or inflatables.
  • Structural engineers — Convert design wind loads specified in mph (US codes) to m/s or km/h for calculations using international standards.

Tips for Accurate Wind Speed Conversions

Wind speed measurements are typically taken at a standard height of 10 metres above the ground. Readings at different heights can differ significantly due to surface friction; a wind of 20 m/s at 10 m may be 25–30 m/s at 100 m hub height for a wind turbine. This converter handles the unit arithmetic precisely — always make sure the wind speed value you enter reflects the correct measurement height for your application.

Use the adjustable Decimal Places setting to match the required precision. A value of 2 is appropriate for weather forecasts, while 4 or more may be needed for engineering calculations. The converter displays the exact conversion factor applied so you can verify the arithmetic yourself.

Frequently Asked Questions

Is the Wind Speed Converter free?

Yes, Wind Speed Converter is totally free :)

Can I use the Wind Speed Converter offline?

Yes, you can install the webapp as PWA.

Is it safe to use Wind Speed Converter?

Yes, any data related to Wind Speed Converter only stored in your browser (if storage required). You can simply clear browser cache to clear all the stored data. We do not store any data on server.

How does the Wind Speed Converter work?

Enter a wind speed value, select the source unit (m/s, km/h, mph, knots, or ft/s), and the converter instantly shows the equivalent in all other units. It also displays the corresponding Beaufort Wind Force Scale number and description so you can understand the wind's observable effects.

What units does the Wind Speed Converter support?

The converter supports five standard wind speed units: meters per second (m/s), kilometers per hour (km/h), miles per hour (mph), knots (kn), and feet per second (ft/s). These cover meteorology, aviation, maritime navigation, and everyday weather reporting.

What is the Beaufort Wind Force Scale?

The Beaufort scale is a 13-level empirical scale (Force 0 to Force 12) that relates wind speed to observable sea and land conditions. Force 0 is calm (< 1 knot), Force 7 is a near gale (28–33 knots), and Force 12 is hurricane force (64+ knots). It was devised by Admiral Francis Beaufort in 1805 and is still used in marine weather forecasting.

Why is wind speed measured in knots in aviation and maritime contexts?

Knots (nautical miles per hour) are used in aviation and maritime navigation because distances at sea and in the air are measured in nautical miles, which are defined by the Earth's latitude. One knot equals exactly 1.852 km/h. METAR weather reports, TAF forecasts, and nautical charts all use knots for consistency with navigation instruments.

How accurate are the wind speed conversions?

All conversions use exact internationally defined factors: 1 m/s = 3.6 km/h, 1 m/s = 1.94384 knots, 1 m/s = 2.23694 mph, and 1 m/s = 3.28084 ft/s. The adjustable precision (0–10 decimal places) lets you control how many digits appear in results.

Can I use this tool for hurricane or storm wind speed conversions?

Yes. The converter accepts any non-negative value up to extreme wind speeds. Values above typical hurricane thresholds (64+ knots / 74+ mph) will show Force 12 on the Beaufort scale, marked as Hurricane Force. The tool is accurate for the full range from calm (0) to violent storm or beyond.