Planning to paint a room, install wallpaper, or estimate wall materials? Use this Wall Area Calculator to find the total wall area from your wall dimensions. Subtract doors and windows to calculate the net area, and add extra allowance to account for cutting, touch-ups, and waste.
Enter the same length for each wall. If your walls have different lengths, calculate each group separately and add the results together.
Enter the combined area of all door and window openings in square meters (m²), regardless of the selected wall measurement unit. Paint coverage varies by product and surface condition, so check the paint container for its stated coverage.
This calculator provides an estimate for planning purposes. Actual paint usage depends on the surface texture, porosity, application method, paint type and product coverage. The calculation assumes the walls have the same height and length. It does not include ceilings or other surfaces.
How to Calculate Wall Area
To calculate wall area, multiply the wall length by its height. If a room has multiple walls, calculate each wall’s area and add them together. Subtract the area of doors and windows to find the net wall area.
The Wall Area Calculator does these calculations for you and can also estimate how much paint you may need, based on the selected coverage rate and number of coats.
Examples
Example 1: One wall
A wall is 12 feet long and 9 feet high.
- Gross wall area: 108 square feet
- Door and window area: 0 square feet
- Net wall area: 10.03 m²
Example 2: Four walls
A room has four walls, each 12 feet long and 9 feet high.
- Gross wall area: 432 square feet
- Door and window area: 4 m²
- Net wall area: 36.12 m²
Example 3: Estimating paint
If the net wall area is 36.12 m², you add 10% extra allowance, apply two coats, and use paint covering 10 m² per liter. The estimated paint requirement is approximately 7.95 liters.
Frequently Asked Questions
1. How do I calculate wall area?
Multiply the wall length by its height. For multiple walls, add their individual areas together.
2. Should I subtract doors and windows?
Yes. Subtract their combined area to estimate the actual wall surface that needs painting or covering.
3. How much paint do I need for a wall?
Divide the wall area by the paint’s coverage per liter, then multiply by the number of coats. Add an allowance for waste where appropriate.
4. Can I use different measurement units?
Yes. You can enter wall dimensions in meters, centimeters, millimeters, feet, or inches. The calculator displays area results in square meters (m²).
Note: Paint requirements are estimates. Surface condition, paint type, application method, and manufacturer coverage can affect actual consumption.