Wind Speed Converter & Wind Strength | Convert m/s, km/h, Knots and mph, Beaufort Scale, What a Given Wind Speed Does, Typhoon Intensity, Wind Pressure and Force, Wind Chill and Wind Speed by Height
The Wind Speed Converter answers questions such as “how strong is a 15 m/s wind?”, “how do I convert knots to m/s?”, “how many kg of force does a 20 m/s wind put on a sign?”, “how much colder does a 10 m/s wind make it feel?” and “how much stronger is the wind 30 m up?”. It converts wind speed between m/s, km/h, knots (kt), mph and ft/s, and shows the Beaufort force (0 to 12, as used by the Japan Meteorological Agency) with land and sea descriptions, the JMA forecast wording (“fairly strong”, “strong”, “very strong”, “violent”) with the effects on people, trees, cars and buildings from JMA’s wind strength table, and typical gusts (1.5 to 3 times the mean). It also gives typhoon intensity (strong 33 m/s, very strong 44 m/s, violent 54 m/s) alongside hurricane categories, the force on a sign, umbrella or person (N and kgf) from the dynamic pressure ½ρv², the feels-like temperature with the wind chill index, the Linke formula and the Steadman formula plus a temperature × wind table, wind speed by height using the power law with the terrain categories of Japan’s Building Standards Act, a 16-point compass converter, and reference tables for the Beaufort scale, forecast terms, typhoons and unit conversion.
Convert wind speed and see how strong it is
Enter a forecast wind speed (a 10-minute average) to convert it to km/h, knots and mph and see its Beaufort force and what that wind actually does.
m/s (metres per second)
10.00
km/h (kilometres per hour)
36.0
Knots (kt)
19.4
mph (miles per hour)
22.4
ft/s (feet per second)
32.8
Force 5 (Fresh breeze)
8.0 to under 10.8 m/s
On land
Small trees in leaf begin to sway; crested wavelets on ponds and lakes
At sea (wave height in the open ocean)
Moderate waves with many whitecaps; some spray
2 m (max 2.5 m)
Japanese forecast wording (JMA terms)
Fairly strong wind (10–15 m/s)
Typical gusts
15.0–30.0 m/s
Gusts can be 1.5 to 3 times the mean wind
If it were a typhoon (as the maximum wind)
Not a typhoon (below 17.2 m/s it is a tropical depression)
Wind pressure on a 1 m² board
About 74 N (about 7.5 kgf)
Dynamic pressure 61 Pa × drag coefficient 1.2
What this wind does (summary of JMA’s wind strength table)
Hard to walk into the wind and you cannot use an umbrella. Whole trees and power lines begin to sway. On expressways you feel pushed by crosswinds. Gutters begin to shake.
Wind direction (degrees) to 16 compass points
Wind direction is where the wind blows from. A north wind blows from north to south. North is 0°, east 90°, south 180° and west 270°.
16-point compass
North wind
N
The arrow shows the direction the air is moving.
Results are estimates. Actual damage depends heavily on wind direction, terrain and the condition of buildings. When strong winds are forecast, check official weather information and local evacuation advice.
ABOUT
About Wind Speed Converter & Wind Strength | Convert m/s, km/h, Knots and mph, Beaufort Scale, What a Given Wind Speed Does, Typhoon Intensity, Wind Pressure and Force, Wind Chill and Wind Speed by Height
The Wind Speed Converter is a free tool that converts wind speed between m/s, km/h, knots and mph and shows the Beaufort force (JMA wind force scale) and what that wind typically does to people, trees, cars and buildings. It also calculates typhoon intensity, the wind pressure and force on a sign or umbrella, the feels-like temperature from air temperature and wind, and how wind speed changes with height.
How to use Wind Speed Converter & Wind Strength | Convert m/s, km/h, Knots and mph, Beaufort Scale, What a Given Wind Speed Does, Typhoon Intensity, Wind Pressure and Force, Wind Chill and Wind Speed by Height
- 1Enter a wind speed, for example from a forecast, and choose its unit (m/s, km/h, knots, mph or ft/s)
- 2Check the conversions to the other units, the Beaufort force, the forecast wording and the typical effects
- 3For the feels-like temperature, enter the air temperature and humidity on the Wind chill tab
- 4For the force on a sign, umbrella or person, choose the area and shape on the Wind pressure tab
- 5For the wind on a high floor or at drone altitude, choose the heights and surroundings on the Height tab
Great for
- Finding out how strong a forecast “15 m/s wind” really is and whether you can use an umbrella
- Converting knots used in sailing, fishing and aviation weather to m/s or km/h
- Checking how many m/s Japan’s “strong”, “very strong” and “violent” typhoons are and comparing them with hurricane categories
- Estimating how many kg of force a sign, banner or laundry pole takes before a typhoon
- Knowing the feels-like temperature in wind when climbing, fishing or camping in winter
- Estimating how much stronger the wind is on a high-rise balcony or at drone flying height
Good to know
- 1 m/s is 3.6 km/h; 1 knot (kt) is one nautical mile (1,852 m) per hour, about 0.514 m/s; 1 mph is about 0.447 m/s. A 10 m/s wind is 36 km/h or about 19.4 knots, and 15 m/s is 54 km/h or about 29.2 knots.
- Forecast wind speeds are 10-minute averages. Beaufort forces use the boundaries of the JMA wind force scale (the same 0 to 12 as the Beaufort scale): 10 m/s is force 5 (fresh breeze) and 15 m/s is force 7 (near gale). JMA calls 10–15 m/s “fairly strong”, 15–20 m/s “strong”, 20–30 m/s “very strong” and 30 m/s or more “violent”. Gusts can reach 1.5 to 3 times the mean wind.
- Typhoon intensity is based on the maximum wind: 33 m/s or more is “strong”, 44 m/s or more “very strong” and 54 m/s or more “violent”. Size is based on the radius of winds of 15 m/s or more: 500 km or more is “large” and 800 km or more “very large”.
- Wind pressure is the dynamic pressure ½ × air density (1.225 kg/m³) × speed², and the force is that times the area and a drag coefficient (flat board 1.2, open umbrella 1.4, standing person 1.0). At 20 m/s a 1 m² board takes about 294 N (about 30 kgf), and doubling the wind speed quadruples the force.
- The feels-like temperature uses the North American/UK wind chill index (10°C or below, 1.3 m/s or more), the Linke formula (temperature − 4√wind speed) and the Steadman formula, which also uses humidity. Wind speed by height uses the power law with the terrain categories of Japan’s Building Standards Act (α = 0.2 for residential areas, for example). All results are estimates; real damage and comfort depend on terrain, buildings and clothing.
Questions this tool answers
Use Wind Speed Converter & Wind Strength | Convert m/s, km/h, Knots and mph, Beaufort Scale, What a Given Wind Speed Does, Typhoon Intensity, Wind Pressure and Force, Wind Chill and Wind Speed by Height for searches like these:
- how strong is 15 m/s wind can you walk
- 10 m/s wind umbrella
- knots to m/s conversion
- wind speed m/s to km/h
- typhoon violent very strong wind speed
- 20 m/s wind force on sign kg
- wind chill per 1 m/s
- high-rise apartment wind speed how many times
- beaufort scale table m/s
- wind direction degrees 16 point compass
FAQ
- How strong is a 15 m/s wind?
- It is 54 km/h or about 29 knots, force 7 (near gale) on the Beaufort scale and a “strong wind” in Japanese forecasts. According to the JMA wind strength table, you cannot walk into it, some people fall over, and signs and sheet-metal panels start to come loose. Gusts of 20 to 40 m/s are possible.
- Can I use an umbrella in a 10 m/s wind?
- 10 m/s (36 km/h) is where Japanese forecasts start saying “fairly strong wind”, and JMA describes it as too strong for an umbrella. Walking into the wind gets hard and whole trees and power lines start to sway. An open umbrella (about 0.9 m²) takes a force of about 77 N (about 8 kgf).
- How do I convert knots to m/s?
- Multiply the knots by 0.514 (1 knot = 1,852 m per hour ÷ 3,600 seconds). 20 knots is about 10.3 m/s, or about 37 km/h if you multiply by 1.852. To go from m/s to knots, multiply by about 1.944.
- How much force does a 20 m/s wind put on a sign?
- For a flat 1 m² sign facing the wind, the dynamic pressure is ½ × 1.225 × 20² = 245 Pa; times the drag coefficient 1.2 that is about 294 N, or about 30 kgf. At 30 m/s it is about 67 kgf, since force grows with the square of the wind speed.
- How much colder does each 1 m/s of wind feel?
- Mountaineers say about 1°C per 1 m/s. The formulas differ: at 0°C with a 10 m/s wind, the wind chill index gives about −7°C, the Steadman formula at 60% humidity about −10°C and the Linke formula about −13°C.
- Is the wind stronger on a high apartment floor?
- Yes, wind increases with height. In a residential area (terrain category III, α = 0.2), a 10 m/s wind at 10 m becomes about 12.5 m/s around the 10th floor (about 30 m) and about 15.8 m/s at 100 m. Because force goes with the square of speed, it is about 1.55 times as strong at 30 m.
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