How much paint do you need for a 20×20 ceiling?
A 20×20 ft ceiling is 400 sq ft. Two coats on smooth drywall take 2.29 gallons — buy 2 gallons + 2 quarts of flat ceiling paint.
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Your results
Ceiling paint to buy2 gallons + 2 quarts
Ceiling area400 sq ft
Exact paint (2 coats)2.29 gal
Coverage used350 sq ft per gallon
Ceiling paint for 20×20 by texture
| Ceiling | 1 coat | 2 coats |
|---|
| Smooth ceiling | 1 gallon + 1 quart | 2 gallons + 2 quarts |
| Light texture | 1 gallon + 2 quarts | 3 gallons |
| Popcorn / heavy texture | 2 gallons | 4 gallons |
The math
20 × 20 = 400 sq ft × 2 coats ÷ 350 = 2.29 gal
Common questions
How much paint for a 20x20 ceiling?
2 gallons + 2 quarts for two coats on a smooth ceiling; 4 gallons for a popcorn ceiling.
Want the full method, tips and other sizes? See the ceiling paint calculator guide.
Last reviewed November 1, 2026. Results are estimates — confirm with your supplier.
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