Wall Area Calculator

Calculate wall square footage from wall length and height. Estimate total wall area, net wall area after doors and windows, paint coverage, wallpaper rolls, drywall sheets, material quantity, waste, and project cost.

Calculate Wall Area

Wall Area = Wall Length × Wall Height. Net Wall Area = Gross Wall Area − Door Area − Window Area.
Your result will appear here.

How the wall area calculator works

Single wall mode:
The calculator multiplies wall length by wall height, then subtracts door and window openings.

Multiple walls mode:
The calculator multiplies one wall area by the number of same-size walls.

Room walls mode:
The calculator uses room perimeter times wall height to estimate the total wall area around a room.

Known area mode:
The calculator starts from your known wall area, subtracts openings, adds waste, and estimates materials and cost.

Why use a wall area calculator?

A wall area calculator helps estimate wall square footage for paint, wallpaper, drywall, siding, paneling, tile, insulation, and remodeling projects.

It can help calculate gross wall area, net wall area, opening deductions, material quantity, waste, and estimated project cost.

What your result means

Your result shows gross wall area, door area, window area, total opening area, net wall area, area with extra waste, estimated material units needed, and estimated cost.

Wall area formulas

Frequently asked questions

How do I calculate wall area?

Multiply wall length by wall height. For example, a 12 foot by 8 foot wall has a gross area of 96 square feet.

Should I subtract doors and windows from wall area?

Yes, if you want net wall area for paint, wallpaper, panels, or other wall materials. Subtracting openings gives a more accurate material estimate.

How do I calculate wall area for a room?

Add the room length and width, multiply by 2 to get the room perimeter, then multiply by wall height.

How much wall area does one gallon of paint cover?

Many paint estimates use about 350 square feet per gallon, but actual coverage can vary by paint type, surface texture, color change, primer, and number of coats.

Should I add waste for wall materials?

Yes. Add extra for cuts, seams, mistakes, texture, pattern matching, overlap, and trim. Common waste ranges from 5% to 15%, depending on the material.