Wind Load Calculator

ASCE 7-22 uses the Directional Procedure (Chapters 26-31) for Main Wind Force Resisting System (MWFRS) loads. Enter basic wind speed, building dimensions, exposure category, and roof parameters. The calculator computes velocity pressure, exposure coefficients, and design wind pressures for all building surfaces.

MWFRS (Main Wind Force Resisting System) loads apply to the overall structural frame—beams, columns, shear walls. C&C (Components and Cladding) loads apply to individual elements like roof panels, windows, doors. MWFRS uses larger tributary areas and lower pressures; C&C uses smaller areas with higher localized pressures.

Exposure B (urban/suburban): Kz = 0.57-1.03. Exposure C (open terrain): Kz = 0.85-1.20. Exposure D (coastal): Kz = 0.95-1.27. Higher exposure = higher wind speeds at building height = higher design pressures. Exposure D requires 1.15× higher pressures than Exposure B at 30 ft height.

Flat roofs (≤10°): Uniform uplift on entire roof. Low slopes (10-30°): Windward positive pressure, leeward negative (uplift). Steep slopes (>30°): Windward positive, leeward near-zero. Hip roofs reduce corner zone pressures compared to gable roofs. The calculator handles all roof types per ASCE 7-22.

ASCE 7-22 applies a 0.85 directionality factor (Kd) for buildings. This accounts for wind not always hitting the worst-case orientation. The calculator automatically applies Kd = 0.85 for enclosed buildings. For open structures, Kd may be 0.90-0.95.

Importance Factor (Iw) depends on Risk Category: Category I (low hazard): Iw = 0.87. Category II (normal): Iw = 1.00. Category III (high occupancy): Iw = 1.15. Category IV (essential facilities): Iw = 1.15. Higher importance = higher design wind loads for critical structures.