Calculate the area of one or more rectangular walls using their width and height. Subtract doors and windows to find your net wall area in square feet and square meters.
Enter your wall measurements, optionally deduct doors and windows, then calculate the surface area you plan to cover.
Select feet, meters, inches, or centimeters before entering measurements. Use the selected unit for every wall, door, and window dimension. Changing the unit does not convert measurements already entered.
Enter the horizontal width and vertical height of your first rectangular wall. Select Add Another Wall for additional walls, including walls with different dimensions. Enter each wall face only once.
Under the relevant wall, select Add Door or Window. Choose the opening type and enter its width and height. Use quantity for identical openings on that wall; add separate entries when their sizes differ. Skip this step if you do not need any deductions.
Select Calculate Wall Area to view the total wall area, opening deductions, and net area in sq ft and m². The wall breakdown shows the net surface area of each wall. Material quantities and waste allowances are not included.
Keep your measurements accurate: Count each wall face and opening once. Deduct openings from the wall they belong to. After editing any input, calculate again to refresh the results, or use Clear All to start over.
See how the areas of four rectangular walls are added together, then doors and windows are deducted to find the net wall surface area.
A rectangular room measures 12 ft by 10 ft, with four walls that are each 8 ft high.
Select Feet (ft) in the calculator. Count each wall face and opening once.
Two longer walls: 2 × 12 × 8 = 192 sq ft.
Two shorter walls: 2 × 10 × 8 = 160 sq ft.
Combined area: 192 + 160 = 352 sq ft.
Door: 3 × 7 = 21 sq ft.
Windows: 2 × 3 × 4 = 24 sq ft.
Combined deductions: 21 + 24 = 45 sq ft.
Net wall area: 352 − 45 = 307 sq ft.
In square meters: 307 × 0.09290304 ≈ 28.52 m².
Entering this example: Enter four separate walls: two with a width of 12 ft and two with a width of 10 ft, all with a height of 8 ft. Add the door and windows under the walls where they are located. Use a quantity of two only if both identical windows are on the same wall; otherwise, enter one under each relevant wall. Select Calculate Wall Area. The result excludes the ceiling, door and window reveals, and any material waste allowance.
Your net wall area is a starting point for planning. Check which surfaces and material requirements your project needs before ordering supplies.
Subtracting a door or window removes its opening area. The calculator does not automatically add reveals: the narrow surfaces inside the opening. Recessed sides and other small surfaces may also need covering.
Wall area alone does not determine the paint quantity. Enter your net area in the Paint Calculator, then use the coverage stated for your chosen paint and the number of coats you plan to apply. Estimate primer separately if it is needed.
Net wall area does not include cutting waste or rounding up to full boxes, sheets, or rolls. Tile layouts and wallpaper pattern repeats can change the purchase quantity, so area alone may not be enough to plan your order.
This calculator provides an area measurement. Preparation, repairs, removal, trims, materials, and installation need separate cost estimates. For a quote per square foot or square meter, confirm which surfaces and services are included.
Find answers about wall measurements, opening deductions and what your calculated area includes.
Gross wall area is the sum of each wall’s width multiplied by its height. Net wall area is the gross area minus the doors and windows you enter. If you do not add any openings, the gross and net results will be the same.
Yes. Add a separate entry for each wall and enter its width and height. For a rectangular room with a uniform wall height, the gross wall area also equals 2 × (room length + room width) × height. Add each opening under the wall where it is located.
Use decimal feet or convert the full measurement to inches. For example, 8 ft 6 in equals 8.5 ft or 102 in. Select the corresponding unit before entering measurements and use it for every wall and opening dimension. Do not enter 8.6 to represent 8 ft 6 in. Changing the selected unit does not automatically convert values already entered.
This calculator accepts rectangular walls. Using the maximum width and height of a sloped wall can overestimate its area. Calculate the actual shape separately: a triangle has an area of base × perpendicular height ÷ 2. You can use the Square Footage Calculator for supported shapes, then subtract any opening areas separately.
Each opening needs positive dimensions and a whole-number quantity of at least one. Its width and height cannot exceed the corresponding wall dimensions, and the combined opening area cannot exceed that wall’s area. Check the selected unit, dimensions and quantities. These checks do not verify the physical placement of openings, so make sure entries do not overlap.
Each wall entry represents one wall face. The calculator does not automatically include the opposite side or the ceiling. If your project covers both wall faces, enter each face separately with its relevant openings. Calculate ceiling area separately by multiplying the room’s length by its width.
Use it as a surface area reference. Wallpaper rolls and wall panels also depend on wall height, product dimensions, layout, pattern matching and cutting allowances. A simple net-area division may not reflect usable coverage, especially where full strips or sheets are needed around openings. Check your chosen product’s installation guidance before ordering.
It calculates wall area only. Paint quantities require product coverage and the planned number of coats. For tiles, enter your net wall area in the Tile Calculator using its direct-area option, then add tile dimensions, waste allowance and optional box details.
Enter your wall measurements and add any doors or windows you want to deduct. Get your gross and net wall area in square feet and square metres.
Use the Wall Area Calculator