How to Measure

Inside Mount

Measure the inside of the window opening. Take 3 widths and 3 heights, then use the smallest measurement. Do not make your own deductions.

Inside Mount Outside Mount
1

Inside Mount

Measure the full inside window opening from inside edge to inside edge..

2

Measure the Width

Measure at the top, middle and bottom. Use the smallest width.

Inside mount width measurement guide
3

Measure the Height

Measure at the left, centre and right. Use the smallest height.

Inside mount height measurement guide
4

Enter the Smallest Size

Enter the smallest width and smallest height you measured. Do not make your own deductions.

Width first, then height.
Example: W 28 1/2" × H 36 1/4"