This is an estimate. Surface texture, application method, waste, primer, and the paint product’s actual coverage can change the amount needed.
How to use this calculator
Enter the requested values, review any options that affect the calculation, and select Calculate. The main answer appears beside the form, with supporting details below it.
How the calculation works
Paintable area = perimeter × wall height − door area − window area. Paint required = paintable area × coats ÷ coverage.
Example
A 12 × 10 ft room with 8 ft walls, one 20 ft² door, two 15 ft² windows, two coats, and 350 ft² coverage needs about 1.73 gallons.
Related calculators
Frequently asked questions
Does the estimate include the ceiling?
No. It estimates the four walls of a rectangular room.
Why can I edit coverage?
Paint products and surfaces vary. Use the coverage printed on the product you plan to buy.