1. Measure wall dimensions
Measure wall height × width in feet. Multiply for total wall area.
What is wall with window square footage?
Wall-with-window square footage equals wall area minus window area. Apply Area = (wall height × wall width) − (window height × window width). For solid walls, use the wall calculator; for paint coverage, the paint calculator.
Getting started
How to Calculate Wall with Window Square Footage
To calculate wall-with-window square footage, measure wall height × width for total wall area. Measure each window height × width for window area. Subtract total window area from wall area for paintable surface.
2. Measure window area
Measure each window height × width. Sum all window areas on the wall.
3. Subtract windows
Paintable area = wall area − total window area.
Quick reference
Reference
1 acre = 43,560 square feet
1 square yard = 9 square feet
1 square meter = 10.764 square feet
1 square inch = 0.00064516 square feet
Material pricing
Calculate Cost of Materials
Wall paint costs $25-50 per gallon covering 350-400 sq ft. Multiply net wall area by price per gallon for paint cost.
There are 2 steps to calculate material cost:
- Enter the price per gallon of paint or per square foot of wallpaper.
- The Square Foot Calculator multiplies the net wall area (after window subtraction) by your unit price for material cost.
Add 5-10% extra paint for window frame edges and detailed trim work.
Calculating Square Footage for Walls
Measure the wall width and the wall height in feet. Multiply the width by the height to get the total wall area in square feet. Subtract the area of any doors or windows to find the exact paint coverage required. A wall that is 12 feet wide and 8 feet tall has a total area of 96 sq ft. A 3 ft × 4 ft window removes 12 sq ft, leaving 84 sq ft of paintable surface.
To subtract multiple windows of the same size from one wall, multiply the window width by the number of windows. Enter the total as the window width in the Square Foot Calculator. Height remains the height of one window.
FAQ
Frequently Asked Questions
How do I calculate wall area minus a window?
Calculate total wall area (Height x Width), then subtract window area (Height x Width). A 10x8 wall with a 4x3 window = 80 - 12 = 68 sq ft of paintable area.
How do I account for multiple windows on one wall?
Calculate the area of each window and subtract all window areas from the total wall area. For identical windows, multiply one window area by the number of windows.
Should I subtract the window frame from calculations?
For most painting projects, subtract the entire window opening including the frame. If you plan to paint the frame, keep it in your calculations.
How much paint do I need for a wall with windows?
Calculate the net wall area (wall minus windows), then divide by 350-400 sq ft per gallon. This gives you the paint needed per coat.
Can I use this for walls with doors too?
Yes, treat a door as a window opening. Enter the door width and height as the window dimensions to subtract it from the wall area.
What if my window has an irregular shape?
For arched or round-top windows, calculate the rectangular portion plus the curved section. Use the circle calculator for the arch area and add it to the rectangular window area.
REFERENCES
Further Reading & References
Trusted external sources and related sections on this site. External links open authoritative references on Wikipedia and government agencies.
Explore this Square Foot Calculator site
Authoritative external references
- WIKIWall — Wikipedia
- WIKIWindow — Wikipedia
- WIKIDrywall — Wikipedia