How Much Paint Do I Need Per Gallon?
Paint coverage explained — square feet per gallon, coats, and how surfaces change the math.
A gallon of interior paint covers roughly 350 to 400 square feet per coat on a smooth, primed wall — but the real number swings a lot with surface texture, porosity, and the number of coats. Here's what to expect, and how to turn it into gallons.
Paint coverage by surface
| Surface | Coverage per gallon (per coat) |
|---|---|
| Smooth, primed wall | 350–400 sq ft |
| Textured or porous wall | 250–300 sq ft |
| New, unprimed drywall | 200–300 sq ft |
| Rough masonry or stucco | 150–200 sq ft |
Plan for two coats in most cases — it's standard for even color and durability, especially over a different base color. To estimate gallons: take the wall area, subtract doors and windows, multiply by the number of coats, and divide by the coverage figure for your surface. Always round up to whole gallons.
Frequently asked questions
How many square feet does a gallon of paint cover?
About 350–400 sq ft per coat on a smooth, primed surface — less on textured, porous, or unprimed walls.
How many coats of paint do I need?
Two is standard for even coverage and durability. One coat may suffice for minor touch-ups or repainting a similar color.
Do I need primer first?
Use primer on bare drywall, raw wood, stained areas, or when making a big color change. It also stretches your topcoat further.