Wind Load Calculator — Force on Structures & Surfaces
Estimate the drag force that wind exerts on any surface — a building face, billboard, solar panel or road sign. Select the surface shape for a preset drag coefficient, or enter your own, and see how force scales with wind speed squared.
m/s
m²
Surface / shape
Total drag force on the surface at the entered wind speed
- 1
Dynamic pressure: ½ρV²
0.5 × 1.225 × 30² = 551.3 Paρ = 1.225 kg/m³ at sea level, 15 °C (ISO 2533). - 2
Effective surface pressure: q × Cd
551.3 Pa × 1.05 = 578.8 Pa - 3
Wind force: pressure × area
578.8 Pa × 10 m² = 5,788
How does this calculator work?
Wind load F = ½ρV² × Cd × A. Air density at sea level is 1.225 kg/m³; Cd ranges from 0.04 (streamlined) to 1.30 (flat plate). Force scales with wind speed squared — doubling the wind quadruples the load. Consult structural codes for design-level calculations.
Formula
How this is calculated
Wind exerts a force on any object in its path. The magnitude depends on the dynamic pressure of the moving air (q = ½ρV², where ρ = 1.225 kg/m³ at sea level and 15 °C, V is wind speed in m/s), the exposed area perpendicular to the wind, and the shape of the surface described by its drag coefficient Cd.
The drag coefficient captures how efficiently the shape converts kinetic energy into a pushing force. A flat plate perpendicular to the wind has Cd ≈ 1.28; a streamlined aerofoil can achieve Cd < 0.05. For rectangular buildings, Cd ≈ 1.0–1.3 depending on aspect ratio. Because force scales with V², doubling wind speed quadruples the force — which is why design codes specify extreme-value wind speeds carefully.
This calculator gives a first-principles aerodynamic estimate. Structural codes such as EN 1991-1-4 (Eurocode 1) and ASCE 7 add further factors for terrain roughness, building height, topographic amplification, gust factors, and internal/external pressure differences. For code-compliant structural design, consult those standards and a structural engineer.
Frequently asked questions
Dynamic pressure (q = ½ρV²) is the kinetic energy per unit volume of the moving air mass. It represents the pressure a perfectly efficient bluff body could extract from the wind. Multiplied by the exposed area and drag coefficient it gives the actual force.
Because dynamic pressure is proportional to V². Double the speed → four times the pressure → four times the force. A 20% increase in design wind speed therefore raises the load by 44%, making the choice of design wind speed critical for structural safety.
Building codes (ASCE 7, Eurocode 1, AS/NZS 1170.2) add terrain roughness, height amplification, topographic effects, gust factors and internal-pressure coefficients. This calculator gives the base aerodynamic force useful for education and preliminary sizing — use a code-based method for structural design.
Also known as
TG we-Calculate Editorial Team. (2026). Wind Load Calculator — Force on Structures & Surfaces [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/wind-load-calculator
TG we-Calculate Editorial Team. "Wind Load Calculator — Force on Structures & Surfaces." TG we-Calculate. 2026. https://we-calculate.com/calculator/wind-load-calculator.
TG we-Calculate Editorial Team, "Wind Load Calculator — Force on Structures & Surfaces," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/wind-load-calculator
@misc{wecalculate_wind_load_calculator, title = {Wind Load Calculator — Force on Structures & Surfaces}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/wind-load-calculator}}, year = {2026}, note = {TG we-Calculate} }
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