Wind Load Calculator

How to Use This Calculator

1. Enter wind speed in mph (from ASCE 7 wind maps or local code).
2. Select Exposure Category (B = sheltered, C = open, D = coastal).
3. Enter structure height in feet.
4. Results show velocity pressure and design wind pressure. Use Extended tabs for wall pressure, roof uplift, and hurricane zones.

Formula

Example

Frequently Asked Questions

• How do I calculate wind pressure? ▼
  Per ASCE 7, velocity pressure qz = 0.00256 × Kz × V², where Kz is the exposure coefficient and V is wind speed in mph. Design wind pressure = qz × G × Cp, where G = 0.85 gust factor and Cp = pressure coefficient.
• What is Exposure Category B, C, or D? ▼
  Exposure B applies to suburban areas with trees and low-rise buildings within 1,500 ft. Exposure C is open terrain with scattered obstructions. Exposure D is coastal areas facing large bodies of water — the most severe exposure.
• What is the design wind speed for my area? ▼
  ASCE 7-22 wind speed maps show basic wind speed V by Risk Category. Most US residential areas use 85–115 mph; hurricane zones require 130–200 mph. Check ASCE 7 Figure 26.5-1 or your local building code.
• What are the ASCE 7 pressure coefficients Cp? ▼
  For enclosed rectangular buildings: windward wall Cp = +0.8, leeward wall Cp = −0.5, sidewalls Cp = −0.7. Roof Cp varies from −0.7 to +0.4 depending on pitch and wind direction.
• What wind load does a hurricane impose? ▼
  At 150 mph (typical Cat 4), velocity pressure on an open-exposure structure at 20 ft height is roughly 59 psf. Combined wall and roof loads can impose thousands of pounds of lateral force on a typical home.

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