Free calculatorsWind Load Calculator
Peak velocity pressure and building surface pressures to SANS 10160-3 and EN 1991-1-4. Enter basic wind speed, terrain and building dimensions for the peak velocity pressure qp(z), a live building elevation with pressure and suction arrows, the pressure profile up the height, wall and duopitch-roof zone pressures (D/E/A/B/C, F/G/H/J/I) and a printable step-by-step calc sheet.
Runs the validated STATIX wind engine — verified against 221 benchmarks; SANS 10160-3 / EN 1991-1-4
Inputs
Building
Design code
Wind & terrain
m/s
m
Building geometry
m
m
m
deg
Internal pressure Cpi
Openings & internal pressure (EN 7.2.9)
Building — wind zones (3D)
Zone layout — side wall & roof plan
Building section
Pressure profile qp(z) up the height
Wind pressures
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enter data
| Basic velocity pressure qb | — |
| Exposure factor ce(z) | — |
| Peak velocity pressure qp | — |
| Slenderness h/d | — |
| Windward wall net (D) | — |
| Leeward wall net (E) | — |
| Governing roof uplift | — |
| Governing net pressure | — |
Zone pressures
Vertical walls — external Cpe,10 & net pressure (kPa)
Duopitch roof — external Cpe,10 & net pressure (kPa)
Net w = qp(Cpe − Cpi). Positive = pressure onto surface, negative = suction (outward). Both internal cases shown; the governing case per zone is the larger magnitude.
Local peak & opening internal pressure
Internal pressure Cpi from openings EN 7.2.9
Cladding / fixings — local peak Cpe,1 (loaded area ≤ 1 m²) & net
Duopitch roof — local peak Cpe,1 & net
Cpe,1 applies to small loaded areas (cladding panels, fixings, purlins, area ≤ 1 m²) and is more onerous than Cpe,10, especially at edge/corner zones (EN 1991-1-4 Tbl 7.1 / 7.4a). Local net w1 = qp(Cpe,1 − Cpi), governing internal case per zone. The Cpi basis is set in the Inputs panel per EN 1991-1-4 cl 7.2.9.
Design checks
Step-by-step calculation
Combined pressure schedule — all buildings
Every building in the project, aggregated. Each row is one wall or roof zone (D/E/A/B/C, F/G/H/J/I) with its external Cpe, governing internal Cpi, net Cp, peak velocity pressure qp and net surface pressure. Use “Add building” above to build the full schedule, then Download PDF (print → Save as PDF). Net w = qp(Cpe − Cpi).
221
This isn't a toy calculator
It runs the same engine as STATIX — a full structural suite validated against 221 closed-form and code benchmarks across analysis, design and connections — the full 3D modeller with native CBFEM is coming soon. Take the wind pressures straight onto the frame, not just one panel.