How much does a gallon of paint cover?
One US gallon of interior paint covers about 350 to 400 square feet in a single coat on a smooth, primed, previously painted wall. Most cans print 400 square feet, but 350 is the safer number to plan with, because cut-ins, roller absorption, and any surface texture all eat into the claim.
For two coats, halve that: one gallon covers roughly 175 to 200 square feet of wall.
Coverage by container size
| Container | One coat, smooth primed wall | Two coats |
|---|---|---|
| 1 US gallon (3.79 liters) | 350 to 400 sq ft | 175 to 200 sq ft |
| 1 quart (0.95 liters) | about 90 to 100 sq ft | about 45 to 50 sq ft |
| 5 gallon bucket | 1,750 to 2,000 sq ft | 875 to 1,000 sq ft |
| 1 liter | about 10 square meters (108 sq ft) | about 5 square meters |
These are planning figures. The coverage rate printed on your specific can always wins, and it is usually on the back label next to the drying times.
Turning coverage into cans to buy
The arithmetic is the same every time. Work out the area you are painting, multiply by the number of coats, add a little for waste, then divide by the coverage rate and round up, because paint is sold in whole containers.
Net wall area means the wall area with doors and windows taken out. A standard door is about 20 square feet and a standard window about 15 square feet. A waste factor of 10 percent is normal for a straightforward interior room.
Worked example
A 12 by 12 foot room with 8 foot ceilings, one door, and one window:
| Wall perimeter | (12 + 12) × 2 = 48 ft |
| Gross wall area | 48 × 8 = 384 sq ft |
| Less one door and one window | 384 - 20 - 15 = 349 sq ft |
| Two coats | 349 × 2 = 698 sq ft |
| Plus 10 percent waste | 767.8 sq ft |
| At 350 sq ft per gallon | 2.19 gallons, so buy 3 |
| At 400 sq ft per gallon | 1.92 gallons, so buy 2 |
That single difference between a 350 and a 400 coverage rate is the difference between buying two gallons and three. It is worth reading the can before you go to the store. Run your own numbers in the paint calculator.
What reduces the coverage you actually get
- Texture. Orange peel, knockdown, and popcorn finishes all have more surface area than they appear to, and can cut coverage by 15 to 30 percent.
- Porosity. Bare drywall, new plaster, and raw wood drink the first coat. Prime first or expect to lose a third of your coverage.
- Color change. Going from dark to light, or covering a strong red or blue, often needs a third coat regardless of what the can says about coverage.
- Application method. Spraying lays down more paint per square foot than rolling, and loses more to overspray. Brushing cut-ins is the most economical and the slowest.
Frequently asked questions
How many square feet does a gallon of paint cover?
About 350 to 400 square feet for one coat on a smooth, primed wall. Plan with 350 unless your can states otherwise and your walls are in good condition.
Why does the can say 400 square feet when I get less?
The figure on the can is measured on an ideal smooth, sealed, primed surface with even application. Real walls have texture, corners, and absorbent patches, and a roller leaves a thicker film than a lab draw-down. Losing 10 to 15 percent against the printed claim is normal.
How much does a gallon of paint cover with two coats?
Roughly 175 to 200 square feet of wall. Two coats means covering the same area twice, so the effective coverage per gallon is halved.
How much wall does a quart of paint cover?
About 90 to 100 square feet for one coat, which suits an accent wall, trim, or a small bathroom. Two quarts cost more than one gallon at most stores, so compare before buying multiples.
Does primer cover the same area as paint?
Usually slightly less. Primer is often quoted at 200 to 300 square feet per gallon because it is designed to soak into and seal a porous surface rather than sit on top of it.