Paint Guide · 3 min read
Paint coverage per gallon
One gallon of interior wall paint covers about 350 square feet on a smooth surface. That's the honest number — and it's usually less than what the paint can tells you. Here's the real coverage by paint type.
Coverage by paint type
These are real-world numbers from product data sheets, not marketing labels. Smooth and primed = top of the range. Rough or porous = bottom.
| Paint type | Coverage per gallon | Typical use |
|---|---|---|
| Interior wall (flat / eggshell) | 350–400 sq ft | Bedrooms, living rooms |
| Interior wall (satin / semi-gloss) | 300–350 sq ft | Kitchens, bathrooms |
| Interior trim / doors (enamel) | 250–300 sq ft | Baseboards, casings |
| Ceiling paint | 350–400 sq ft | Flat ceilings |
| Exterior latex (lap siding) | 250–300 sq ft | Wood / fiber cement siding |
| Exterior (stucco / brick) | 150–200 sq ft | Textured masonry |
| PVA drywall primer | 300–400 sq ft | New drywall |
| Stain-blocking primer | 250–300 sq ft | Smoke, water, tannin stains |
| Bonding primer | 250–300 sq ft | Glossy or slick surfaces |
| Floor / porch paint | 200–300 sq ft | Concrete, wood decks |
| Cabinet / furniture enamel | 100–150 sq ft | Kitchen cabinets (per coat) |
Numbers assume one coat on a properly prepared surface with a standard nap roller.
Want to skip the math? The calculator applies the right coverage for your setup.
Use the paint calculator →Why the can usually overstates coverage
Paint labels are aggressive. They show you the best case — a factory-smooth, freshly primed wall, rolled by someone who isn't tired. In real life, three things eat into your coverage:
- Surface texture. A knockdown-textured wall soaks up 15–20% more paint than a smooth one.
- Color change. Light over dark (or vice versa) needs more paint, even if coats stay at two.
- Cuts and edges. Corners, trim edges, and around outlets all use extra paint that the "square feet" number ignores.
Practical rule: use the lower end of the coverage range when estimating, and round up. Running out of paint mid-project costs more than leftover paint.
What affects coverage
Surface type
Smooth drywall: best coverage. Popcorn ceiling, stucco, brick, concrete: dramatically less. A rough surface isn't just "more area" — the paint fills the texture and soaks in.
Paint quality
Premium paints (Behr Marquee, Benjamin Moore Aura, Sherwin-Williams Emerald) cover more per gallon because they have more pigment solids. A $60 gallon routinely covers what a $25 gallon needs two coats to match.
Color
White and gray are opaque and cover efficiently. Reds, yellows, and oranges have translucent pigments — you'll get fewer sq ft per gallon because you often need an extra coat for full color.
Roller technique
Under-loaded rollers drag and leave thin spots. Over-loaded rollers waste paint. A proper load covers smoothly with even pressure. If you're burning through paint faster than the label says, check your roller first.
How to estimate coverage for your project
- Measure your wall area in square feet (perimeter × height, minus doors and windows).
- Look up your paint type in the chart above and pick the lower number in the range.
- Divide wall area by coverage per gallon. That's one coat.
- Multiply by the number of coats. Round up to whole gallons.
Example: 400 sq ft of interior wall, satin paint (300 sq ft/gal, lower end), two coats. 400 ÷ 300 = 1.33 gallons per coat. × 2 = 2.67 gallons. Round up: 3 gallons.
FAQ
How many square feet does one gallon of paint cover?
One gallon of interior wall paint covers about 350 sq ft on a smooth, primed surface. Rough or porous surfaces drop to 250–300 sq ft per gallon.
Why is the real coverage lower than the can says?
The label is a best-case estimate. Real walls have texture, edges, and cuts-in that eat extra paint. Expect 10–20% less than the label claims.
How far does a gallon of exterior paint go?
~250–300 sq ft on lap siding, 200–250 on stucco or brick, 300 on smooth fiber cement. Rough surfaces drink more paint.
How much does a gallon of primer cover?
PVA drywall primer: 300–400 sq ft. Stain-blocking and bonding primers: 250–300 sq ft — they're thicker.
How much does a gallon of ceiling paint cover?
About 350–400 sq ft per gallon. Most rooms only need one gallon for the ceiling since ceiling paints are formulated to hide in one coat.