How Much Does a Gallon of Paint Cover?
One gallon of interior paint covers about 350–400 square feet per coat on smooth, primed walls. Two coats on a typical 12×12 bedroom take about 2 gallons.
Coverage by surface
| Surface | Typical coverage per gallon |
|---|---|
| Smooth, previously painted drywall | 350–400 sq ft |
| New drywall (with primer first) | 300–350 sq ft |
| Light texture (orange peel) | 300–350 sq ft |
| Heavy texture, popcorn ceilings | 200–300 sq ft |
| Brick, block, rough stucco | 150–250 sq ft |
These are planning ranges; the coverage printed on the can is the manufacturer's figure for ideal conditions.
Gallons per room (two coats, 8 ft ceilings)
| Room | Wall area | Buy |
|---|---|---|
| 10×10 | 269 sq ft | 2 gallons |
| 10×12 | 301 sq ft | 2 gallons |
| 12×12 | 333 sq ft | 2 gallons |
| 12×16 | 397 sq ft | 2 gallons + 2 quarts |
| 16×20 | 525 sq ft | 3 gallons |
What lowers coverage
- Big color changes, especially covering dark colors with light ones
- Porous surfaces like bare drywall, plaster or masonry
- Rolling paint on too thin — it hides worse, so you need another coat
- Thick-nap rollers on smooth walls hold and waste more paint
The paint calculator subtracts doors and windows, handles any number of coats and rounds to gallons and quarts.