How to Measure Vinyl Windows
From the inside of your home, measure the width of the opening:
Top, Middle, and Bottom.

Identify the narrowest measurement and subtract 1/4 inch. This will serve as the width of the window you’ll order.
Measure the height of the opening: Left side, Middle, Right side.

Identify the shortest measurement and subtract 1/4 inch. This will serve as the height of the window you’ll order.
Repeat this process for each window opening.
If you are unsure of your final measurements, we recommend you consult with a qualified installer.