How to estimate paint
Calculate wall area using twice the sum of room length and width, multiplied by wall height. Subtract openings, multiply by coats, and divide by the coverage printed on your paint can.
Before you buy
This tool assumes 21 square feet per door and 15 square feet per window. Textured walls, porous surfaces, primer, and application methods can change coverage.
Does this include the ceiling?
No. The result estimates walls only. Estimate ceiling area separately as length × width.
Last reviewed: October 2026. This tool performs calculations locally in your browser.