📊 Wind velocity pressure by speed (q ≈ 0.613·V²)
Base velocity pressure (before Kz, gust and Cp). Multiply by Kz·G·Cp for the design pressure:
| Wind speed |
km/h |
q (Pa) |
kgf/m² |
| 30 m/s | 108 | 552 | 56 |
| 40 m/s | 144 | 981 | 100 |
| 50 m/s | 180 | 1533 | 156 |
| 60 m/s | 216 | 2207 | 225 |
📐 Formulas
Wind: q = 0.613·Kz·Kzt·Kd·V² (Pa, V in m/s); design pressure p = q·G·Cp (G ≈ 0.85); force F = p × façade area.
Seismic: V = Cs·W; Cs = SDS/(R/Ie), bounded by SD1/(T·(R/Ie)) and a minimum; period T = Ct·Hˣ. The force is distributed up the height (∝ h^k).
🌍 Naming around the world
Base shear = cortante basal = Erdbebenkraft an der Basis · Velocity pressure = presión dinámica = Geschwindigkeitsdruck · Ductility factor R = factor R = Verhaltensbeiwert q · Exposure = exposición = Geländekategorie · Period = período = Eigenperiode.
❓ Frequently Asked Questions
What is the seismic base shear and how is it calculated?
The base shear is the total horizontal earthquake force at the base of a building: V = Cs·W, where W is the seismic weight and Cs the seismic coefficient. Cs = SDS/(R/Ie), bounded by a maximum SD1/(T·(R/Ie)) and a minimum, where SDS/SD1 come from the seismic zone and soil, R is the ductility of the structural system and Ie the importance factor.
How is the wind force on a building calculated?
First the velocity pressure q = 0.613·Kz·Kzt·Kd·V² (Pa, V in m/s), where Kz depends on the height and the exposure. The design pressure is p = q·G·Cp (G ≈ 0.85, Cp the pressure coefficient), and the total force is F = p × façade area.
Can I use this calculator to design my house or building?
No. This is an educational estimator that uses simplified methods. Real design requires a full analysis to the local code and the calculation and sign-off of a licensed structural engineer. Use these numbers only to understand the orders of magnitude and how a building behaves.