Paint Coverage Calculator

Estimate how much paint you need based on wall area, number of coats, and paint coverage per gallon. If you need to calculate wall area first, use our Wall Area Calculator.

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Wall Area Ceiling Area Room Area Floor Area
Paint Needed: —
Formula:
Total Paint Area = (Wall Length × Wall Height × Walls) − Subtractions
Paint Needed (gallons) = (Total Paint Area × Coats) ÷ Coverage
Example:
600 ft² walls − 40 ft² openings = 560 ft²
2 coats → 1,120 ft² coverage needed
1,120 ÷ 350 ≈ 3.2 gallons

Frequently Asked Questions

How much area does a gallon of paint cover?

Many interior paints cover about 300–400 ft² per gallon per coat. Check your paint label.

Do I need two coats?

Often yes—especially for color changes, new drywall, or high-traffic areas.

Should I subtract doors and windows?

Yes. Subtracting openings improves accuracy.