Size Guide

Find Your Window & Door Size

Standard rough-opening sizes, how to measure correctly, and how custom sizing works.

Standard Window Sizes (Rough Opening)

Common U.S. residential dimensions. All sizes can be customized.

Width × Height (inches)Common UseSeries
24″ × 36″Small bathroom / utilityCasement, Fixed
24″ × 48″Bedroom sideCasement, Double-Hung
30″ × 36″Kitchen / bathAwning, Casement
30″ × 48″Standard bedroomDouble-Hung, Casement
30″ × 60″Tall bedroom / livingCasement, Fixed
36″ × 36″Kitchen over sinkAwning, Slider
36″ × 48″Living room standardDouble-Hung, Casement
36″ × 60″Large living / diningCasement, Picture
48″ × 48″Wide picture windowFixed, Slider
48″ × 60″Grand living / viewPicture, Multi-Slide

How to Measure Your Opening

Measure the rough opening (stud to stud), not the old frame.

1

Measure the Width

Measure across the opening at the top, middle, and bottom. Use the smallest of the three measurements.

2

Measure the Height

Measure from the sill to the header at the left, center, and right. Use the smallest measurement.

3

Measure the Depth

Confirm the wall depth (2×4 / 2×6 construction) so the frame fits flush with interior and exterior finishes.

Need a Non-Standard Size?

Every Lansen window and door is built to your exact dimensions. Send us your rough opening or floor plan and we’ll return an engineer-reviewed quote.

Request Custom Sizing