FREE PROJECT PLANNING TOOL
Estimate paintable wall area and paint quantity from the actual room dimensions, openings, coat count and coverage printed on the can. The result shows the math so you can adjust the plan instead of accepting a black-box number.
How the paint calculator works
The calculator finds wall area from perimeter × height, subtracts doors and windows, multiplies by the number of coats, then divides by the selected coverage rate. The final purchase estimate rounds up to a usable container quantity.
- Enter room length, width and wall height.
- Add door and window counts or their combined area.
- Choose the number of finish coats and the manufacturer’s coverage rate.
- Review net wall area and estimated gallons; plan primer separately when needed.
FREE WALL CALCULATOR
Plan your wall in 60 seconds
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A 12 × 14 ft room with 8 ft walls starts at 416 sq ft of wall surface. After subtracting openings, two coats double the coverage workload. Dividing that figure by the can’s stated square-foot coverage gives the gallon estimate.
Porous drywall, strong color changes and textured walls can use more material than a smooth, previously painted surface. Keep a small labeled amount for future touch-ups and confirm whether the product coverage is stated per coat.
Frequently asked questions
Does the calculator include the ceiling?
No. It estimates room walls. Calculate the ceiling separately as length × width and add it only if you plan to paint it.
Should I subtract doors and windows?
Yes for a closer material estimate, though leaving small openings in can create a modest safety margin.
How many coats should I enter?
Two finish coats are common. Primer, deep colors and major color changes may require a different system. Follow the paint manufacturer’s guidance.
Turn the estimate into a finished wall
Save the measurements, verify them on site and compare materials before ordering. Trim Wall Haus offers pre-cut wall molding options and project support for cleaner DIY planning.
Plan a painted molding wall Wall Square Footage Calculator Browse all wall molding calculators
Planning estimate only. Verify field measurements, product dimensions and local requirements before cutting or installation.