Painting Calculators

Estimate paint, primer, and wallpaper for interior and exterior painting projects.

Calculators

• Paint Calculator
• Primer Calculator
• Wallpaper Calculator

Which measurement should I take first?

Start by measuring wall height and width (or room perimeter) to get square footage — every painting calculator on this site uses that number as its base input. Subtract door and window openings so you don't over-buy. If you're unsure whether a surface needs primer, check the condition of the substrate first: bare drywall, patched areas, stains, or a big color change (dark to light) all call for a primer coat before paint.

Suggested project order

1. Primer — seal bare or patched surfaces before topcoat.
2. Paint — apply your topcoat once primer has cured.
3. Wallpaper— if you're papering instead of (or over) paint, run this last to compare roll counts.