How many square feet does a gallon of paint cover?
A gallon of interior paint covers about 350 to 400 square feet with one coat on a smooth, previously painted wall; that is the figure printed on most cans. Rough, textured or bare surfaces drink more, down to about 175 square feet per gallon on stucco. For a typical 800 square feet of wall at two coats you need 4.6 gallons, so buy 5.
Standard coverage: 350 to 400 square feet per gallon
Paint makers print a coverage figure on the can, usually 350 to 400 square feet per gallon for one coat on a smooth, sealed surface. That number assumes a roller with the right nap, a wall that has been painted before, and a reasonably even film. Divide your wall area by it, multiply by the number of coats, and round up to whole cans. The paint calculator does exactly that and lets you change the coverage to the figure on your can.
| Wall area | One coat (gal) | Buy | Two coats (gal) | Buy | Two coats on smooth walls (400 sq ft/gal) |
|---|---|---|---|---|---|
| 400 sq ft | 1.1 | 2 gal | 2.3 | 3 gal | 2 gal |
| 800 sq ft | 2.3 | 3 gal | 4.6 | 5 gal | 4 gal |
| 1,200 sq ft | 3.4 | 4 gal | 6.9 | 7 gal | 6 gal |
| 1,600 sq ft | 4.6 | 5 gal | 9.1 | 10 gal | 8 gal |
| 2,000 sq ft | 5.7 | 6 gal | 11.4 | 12 gal | 10 gal |
Coverage by surface type
The same gallon goes a lot less far on a surface that is rough or porous. These are the typical figures paint makers give for a first coat; a second coat on the now-sealed surface is closer to the standard number. The last column is one coat on 1,000 square feet.
| Surface | Sq ft per gallon | m² per litre | 1,000 sq ft, one coat |
|---|---|---|---|
| Smooth drywall or plaster, previously painted | 400 | 9.8 | 2.5 gal (buy 3) |
| Lightly textured walls (orange peel, knockdown) | 350 | 8.6 | 2.9 gal (buy 3) |
| New, unprimed drywall (first coat) | 300 | 7.4 | 3.3 gal (buy 4) |
| Wood siding, rough sawn | 275 | 6.7 | 3.6 gal (buy 4) |
| Brick or block, unpainted | 200 | 4.9 | 5 gal (buy 5) |
| Stucco or heavy texture | 175 | 4.3 | 5.7 gal (buy 6) |
One coat or two?
Coverage on the can is per coat. Repainting the same colour on a sound wall can get away with one; anything else needs two, and a strong colour over white or white over a dark colour may need three. Buying for two coats and having a quart left over is cheaper than a second trip and a can that does not quite match the batch.
Spraying versus rolling
An airless sprayer lays paint faster and smoother, but overspray, the mist that never lands on the wall, and the paint left in the hose mean you buy more. A third more is a fair planning allowance on walls; on fences and lattice, where most of the spray passes through, it can be double.
| Wall area | Rolled (gal) | Buy | Sprayed (gal) | Buy |
|---|---|---|---|---|
| 400 sq ft | 2.3 | 3 gal | 3 | 3 gal |
| 800 sq ft | 4.6 | 5 gal | 5.9 | 6 gal |
| 1,200 sq ft | 6.9 | 7 gal | 8.9 | 9 gal |
Metric: square metres per litre
European and Australian cans quote coverage in square metres per litre, typically 10 to 12 m² per litre per coat for emulsion on smooth walls (350 square feet per gallon is about 8.6 m² per litre). Cans come in 2.5 and 5 litre sizes.
| Wall area | Litres | 5 L cans | 2.5 L cans |
|---|---|---|---|
| 20 m² | 4 | 1 | 2 |
| 40 m² | 8 | 2 | 4 |
| 60 m² | 12 | 3 | 5 |
| 80 m² | 16 | 4 | 7 |
| 100 m² | 20 | 4 | 8 |
Before you buy
- Measure the walls, not the floor: wall area is the perimeter of the room times the ceiling height, minus doors and windows. The 12x12 room guide shows the full example, and the room planner does it for several rooms at once.
- Ceilings are a separate surface with their own paint; see how much paint a ceiling needs.
- Buy all the cans of one colour from the same batch and mix them together in a bucket before you start, so the last wall matches the first.
Frequently asked questions
- How many square feet does a gallon of paint cover with two coats?
- Half as much as one coat: 175 to 200 square feet at the usual 350 to 400 per coat. Two coats of one gallon cover a 10 x 10 ft wall with an 8 ft ceiling comfortably, but not a whole room. The tables above assume two coats because that is what a colour change or a fresh wall needs.
- How much paint do I need for a 12x12 room?
- About 1.9 gallons for the walls at two coats, once a door and two windows are taken off; buy 2. The 12x12 room guide has the full worked example with 8, 9 and 10 ft ceilings.
- How many square feet does a gallon of primer cover?
- Less than paint: primer is thinner and soaks into bare surfaces, so 200 to 300 square feet per gallon is typical on new drywall, and less on masonry. Use the coverage printed on the primer can, not the paint can, and count it as its own coat.
- Does one coat of paint cover a wall?
- Only when repainting the same colour in the same sheen on a sound surface. A change of colour, a repair, new drywall, or going from dark to light almost always needs two coats, and dark to light can need three. Plan on two and be pleasantly surprised.
- How much more paint do textured walls need?
- Roughly 10 to 15% more for light texture and 25 to 50% more for heavy texture, popcorn or stucco, because the surface area is larger than the flat area you measured and the roller has to fill the hollows. The table by surface type gives the usual figures.
- Does spraying use more paint than rolling?
- Yes, typically 20 to 40% more, from overspray and the paint left in the hose and cup. Spraying is faster and gives a smoother finish on doors and trim, but on plain walls a roller wastes less. The spray table above adds 30% as a planning figure.
More guides
- How much paint do I need for a 12x12 room?
Gallons of paint for a 12 x 12 ft room with 8, 9 or 10 ft ceilings, one or two coats, a door and two windows deducted, plus the 4 x 4 m room in litres.
- How much paint do I need for a ceiling?
Quarts and gallons of ceiling paint for 10x10, 12x12, 15x15 and 20x20 ft ceilings at one and two coats, plus 3x3 to 5x5 m ceilings in litres.
- How much paint for a 10x10 room? (10x12, 12x14 and 14x16 too)
Gallons of paint for a 10x10 room with an 8 ft ceiling, a door and two windows, one or two coats, plus the ceiling; 10x12 to 14x16 rooms; 3x3 to 4x5 m rooms in litres.
- How many square feet does a quart of paint cover?
A quart covers about 90 to 100 sq ft with one coat: what that means for a door, a wall, trim and a small ceiling at one and two coats, plus litres and 5 gallon pails.
Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.