Glazing Area Calculator
Calculate the net glazing area, frame area, and glass-to-wall ratio for a window opening.
How to Use the Glazing Area Calculator
- Enter window width in metres.
- Enter window height in metres.
- Enter frame width in millimetres.
- Click Calculate for glazing area, frame area, and ratio.
Use Cases
- •Daylight calculation for building permits.
- •Energy modelling inputs.
- •Window specification comparison.
- •Façade design.
Formula
Glazing area = (W − 2×fw) × (H − 2×fw). Frame area = W×H − Glazing area.
Frequently Asked Questions
What is frame width?
Frame width is the thickness of the window frame on each side, typically 50–100 mm.
What is a good glass-to-wall ratio?
Building codes often require 8–10% of floor area as glazing for natural light.
Does this include muntins?
No — this calculates the clear opening minus frame. Mullion and muntin areas would reduce it further.