FullCalculator

Window Size Calculator

Window Area & Glass Size

Calculate window glass area and light exposure

Window Replacement Cost

Estimate the cost of replacement windows

Formula

Glass Area = (W × H) × (1 - Frame %) | Rough Opening = Window Size + 1" | Ventilation = Glass Area × Type Factor

Frequently Asked Questions

What are standard window sizes?
Common residential window sizes: 24"×36", 28"×54", 32"×52", 36"×48", 36"×60". Double-hung windows typically range from 24"-48" wide and 36"-72" tall. Always measure your existing opening before ordering.
How do I measure for replacement windows?
Measure width at three points (top, middle, bottom) and use the smallest. Measure height at three points (left, center, right) and use the smallest. Measure diagonals to check for square. The replacement window should be ordered to the exact smallest measurements.

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