Winda Technical Resources

Wind Load
Calculator

Enter your project conditions to calculate the wind pressure and suction values using the logic and lookup data used in the supplied Winda calculation sheet.

Calculate Your Project ↓

01 / Engineering

Engineering starts with the load.

Wind load changes with location, building dimensions, terrain, building importance, openings and cyclone conditions.

Use the calculator below to obtain a project-specific preliminary wind-load result before system selection.

Project Wind Load Calculator

IS 875 (Part 3) : 2015 · Windows & Façades

Scope: wind pressure on windows, doors, glazing & cladding in the walls of enclosed rectangular buildings (Table 5). Envelope of all wind directions — orientation not required. Roofs, canopies, free-standing walls and non-rectangular forms are outside this tool.

Project

Opening Condition

How much of the façade will have openable windows?

Openings as % of wall area (Cl 7.3.2). A large door, loading bay or open floor that can stay open in a storm → choose > 20%.

Project Conditions

City

V_b from IS 875 (Part 3):2015 Annex A, as amended by Amendment No. 2 (2020). Not listed? Choose “Other location”.

Project type

Sets k₁ (Table 1) and, near the coast, k₄ (Cl. 6.3.4).

Cyclone prone area

East & west coast sites within 60 km of the sea.

Building Dimensions

Building height (h)

Up to the roof / parapet top. Below 10 m, k₂ at 10 m is used.

Building width (w)

Plan dimensions — order does not matter; the shorter side is taken as w.

Building length (l)

What's around the building?

Judge the surroundings once everything nearby is built. On a corner, ridge or facing open ground on one side — choose the more exposed option.

Advanced engineering options

Directionality factor K_d

Non-cyclonic building0.90

Typical zone: 0.90 (Cl 7.2.1), 1.00 when cyclone-prone. Corner strips always 1.00 (conservative).

Site topography (Annex C)

Sets topography factor k₃ = 1 + C·s.

Interference from nearby tall buildings (Cl 8.3)

For a neighbouring building of the same or greater height (Fig 8). Ignore neighbours under one-third of this building's height.

k₃

Flat site1.000

V_b—

k₁—

k₂ at h—

k₄—

V_z m/s—

p_z kPa—

h/w · l/w—

Every factor is shown with its clause in the result — ready for your structural consultant.

Calculation Result

Wind Load Calculation

Design pressure for window / façade selection to IS 875 (Part 3):2015 — final verification by the project structural / façade engineer.

Design +ve · pressure—kPa—

Design −ve · suction—kPa—

Typical zone −ve—

Corner strip width y—

Design wind speed V_z at h—

Façade zones

Windows inside the corner strips (hatched) take the corner suction. All other windows use the typical-zone values.

Height-wise design pressures (kPa)

Height band	k₂	V_z m/s	p_d	+ve	−ve typical	−ve corner

Each band is designed at its top height. Use for floor-wise system selection.

Show full calculation (IS 875-3 : 2015)

Design pressure for window / façade selection to IS 875 (Part 3):2015, walls of enclosed rectangular buildings (Table 5, l/w < 4, h ≤ 500 m). Final verification — profile, glass, hardware, anchoring — by the project structural / façade engineer.