Calculate wall area in square feet from room length, width, wall height and door or window openings. Use the result for paint, drywall, insulation and finishes.
Enter your measurements and material details.
Measure each room separately when wall heights or layouts differ.
This calculator adds the four walls of a rectangular room using perimeter multiplied by wall height, then subtracts the opening area you enter. The net square footage can be carried into paint, wallpaper, insulation or panel calculations.
Measure finished wall length and height rather than relying only on plan dimensions. Large windows, patio doors and openings can be subtracted; small openings are sometimes left in the total when you want a modest practical allowance.
No. This tool calculates vertical wall area only.
You can, but leaving small openings in the total creates a small material allowance.
Yes. Use the net area with your paint coverage and number of coats.
Yes as a square-foot check, although sheet count also depends on sheet size and layout.
Split the room into simpler wall runs or calculate each rectangular section separately.
Using the example inputs shown in the calculator — Room length (ft) = 14, Room width (ft) = 12, Wall height (ft) = 8, Doors and windows (sq ft) = 50 — the result is 366 sq ft. This demonstrates the formula with a complete set of numbers rather than a hidden assumption.
The result breakdown also shows Gross wall area: 416 sq ft; Openings subtracted: 50 sq ft. Replace the example values with field measurements and the exact product coverage, yield or package size you plan to buy.
For this wall area calculator, the inputs with the greatest practical effect are room length, room width and wall height. Recalculate when any of those change; do not reuse a result from a different room, run, layer depth or product specification.
Wall Area Calculator is intended to help with quantity planning and arithmetic. It does not inspect the site, choose structural dimensions, determine code compliance or replace manufacturer installation instructions. Conditions such as slope, substrate quality, moisture, soil, framing, access and workmanship can change the final amount required.
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