Paint Calculator
Enter your room dimensions, coats and openings to see how many gallons of paint you need.
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How Much Paint Do You Need?
Wall area is 2 × (length + width) × height. One gallon of paint covers about 350 sq ft per coat, so multiply the paintable area by the number of coats and divide by 350. We subtract an average door (21 sq ft) and window (15 sq ft) from the total.
Tips
Most walls need two coats, especially over a color change. Buy a little extra for touch-ups, and remember primer if you are covering a dark color or bare drywall.
Painting a ceiling or floor area? Size it with the Square Footage Calculator.
Frequently Asked Questions
About 350 square feet per coat on a smooth surface. Rough or porous surfaces absorb more, reducing coverage.
Usually two. A single coat may work when repainting a similar color over a sealed surface; color changes and new drywall almost always need two.
No, it estimates the four walls. Add the ceiling separately using its length times width if you are painting it too.
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