Window Size Calculator

Calculate window dimensions, rough opening size, and egress compliance. Choose a standard window preset or enter custom measurements.

Window Size Calculator

Results

✓ Egress compliantSingle-Hung

Window Width

36"

Window Height

48"

Rough Opening W

38"

Rough Opening H

50"

Total Area

12.00 ft²

Net Opening

6.00 ft²

Window: 36" W × 48" H  ·  3'-0" × 4'-0" ·  RO: 38" × 50"

Standard Window Size Reference

TypeWidthHeightRough WArea (ft²)
Small Single24"36"26"6.00
Standard Single36"48"38"12.00
Large Single48"60"50"20.00
Wide Double-Hung36"60"38"15.00
Casement 24x4824"48"26"8.00
Casement 30x5430"54"32"11.25
Sliding 48x3648"36"50"12.00
Sliding 72x4872"48"74"24.00
Picture 48x4848"48"50"16.00
Bay Window 96x4896"48"98"32.00
Egress Min 20x2420"24"22"3.33
Egress Standard36"24"38"6.00

Window Type Guide

Single-Hung

Lower sash slides up. Most common residential type.

50% of area

Double-Hung

Both sashes slide. Easy to clean from inside.

50% of area

Casement

Hinged at side, swings outward. Best ventilation.

100% of area

Sliding

Sash slides horizontally. Good for wide openings.

50% of area

Picture

Fixed, no opening. Maximum light, no ventilation.

0% — fixed

Awning

Hinged at top, swings out. Can open in rain.

~80% of area

How to Use

  1. 1Select a preset or type custom width and height
  2. 2Choose the window type for accurate net opening
  3. 3Adjust rough opening allowance if needed
  4. 4Check egress compliance for bedroom windows

Egress Requirements

IRC requires egress windows in all sleeping rooms:

Min Width: 20"

Min Height: 24"

Min Opening: 5.7 ft²

Max Sill: 44" from floor