Planning new glazing or replacement windows? Enter the width and height of your windows to calculate the area of each one and the total for the whole project. This free tool is handy for estimating glass, framing and installation costs.
Window Area Calculator
How to Use
- Measure the width and height of your window in metres.
- Enter how many windows share those dimensions.
- Click “Calculate Area” to see the per-window and total area.
- Repeat for windows of different sizes and add the totals together.
Key Features
- Calculates area for one window or many identical windows.
- Works with any metric measurements.
- Instant results — no data leaves your browser.
- Useful for glazing, framing and cost estimates.
- Free with no sign-up.
FAQs
Should I measure the frame or the glass?
Measure the full window opening including the frame for replacement quotes, or just the glass for glazing film.
Can I use feet instead of metres?
Yes — enter feet and read the result as square feet. Just keep the unit consistent.
Does it account for window shapes?
This calculator assumes rectangular windows. For arched or circular windows, consult a specialist.