Paint can sizes and what each covers
What a quart, a gallon and a 5-gallon bucket of paint cover, when to buy each size, and how many cans a typical room needs.
- Updated October 10, 2026
- By the Paint Gallons editorial team
- 5 min read
The short answer
Interior latex paint in the US is sold mainly in three sizes: the quart, the gallon and the 5-gallon bucket (also called a pail). At a typical rate of 350 to 400 square feet per gallon for one coat, a quart covers roughly 90 to 100 sq ft, a gallon 350 to 400 sq ft, and a 5-gallon bucket 1,750 to 2,000 sq ft. Many single rooms need between 1.5 and 2 gallons for two coats on the walls. Put your room into the paint calculator to get the gallons for your own walls, then use this guide to turn that number into cans.
Always check the label of the paint you are buying. Coverage differs between product lines: one manufacturer quotes 350 to 400 sq ft per gallon as typical, while another maker's line states 400 to 450 sq ft. The size of the can never changes, but what it covers does.
What each size covers
A US gallon holds four quarts, and a 5-gallon bucket holds five gallons, so coverage scales in simple steps. The table below uses the two ends of the typical range for a single coat on a smooth, previously painted wall. For two coats, halve the area each container will finish. New drywall and textured walls absorb more paint, so expect less area from every size on those surfaces; the guide on how paint coverage works explains why.
Small sample jars sit below the quart. They exist for testing a color on the wall, not for painting it: one manufacturer says its 8 oz sample brushes out an area of about 2 ft by 2 ft. Buy samples to compare colors in your own light, then buy the working paint in the sizes below.
| Container | Volume | At 350 sq ft per gallon | At 400 sq ft per gallon | Typical use |
|---|---|---|---|---|
| Sample jar | 8 fl oz | About 4 sq ft (a test patch) | About 4 sq ft (a test patch) | Testing a color |
| Quart | 1/4 gallon | About 88 sq ft | 100 sq ft | Trim, a door, a small accent wall |
| Gallon | 4 quarts | 350 sq ft | 400 sq ft | Walls of one small room, one coat |
| 5-gallon bucket | 5 gallons | 1,750 sq ft | 2,000 sq ft | Several rooms in one color, or a whole floor |
When to buy quarts
Quarts make sense when the job is small or the color is used in only one place. A front door, a run of baseboard, a small bathroom vanity or one accent wall can often be finished with one or two quarts. One paint maker describes a quart as covering about 100 square feet, which is enough for an accent wall or a door.
Quarts also handle the leftover part of a larger estimate. The paint calculator plans whole gallons first, then covers a remainder of up to a quarter gallon with one quart and up to half a gallon with two quarts; anything over half a gallon becomes another gallon instead of three quarts. Compare the quart and gallon prices of your chosen paint before buying several quarts, and note that not every product is offered in quarts; some manufacturers only sell select lines in the smaller size.
When to buy gallons
The gallon is the standard size for walls and ceilings. Most bedrooms, offices and living rooms fall between 1 and 3 gallons for two coats, so buying in single gallons keeps waste low and makes the cans easy to carry and store.
If your estimate lands just over a whole number, such as 2.1 gallons, the calculator plans 2 gallons and 1 quart. That covers the estimate, but if the walls are new drywall, rough or changing from a dark color, the real use will likely be higher than the estimate and a third gallon is the safer choice. Ask the store about its return policy for tinted paint before counting on returning a spare can.
When a 5-gallon bucket makes sense
A 5-gallon bucket fits large jobs in one color: an open-plan floor, a whole house interior painted the same white, or ceilings across several rooms. The calculator plans one as soon as an estimate reaches 5 gallons, and switches five single gallons to a bucket. A bucket gives you a single, evenly mixed batch and avoids running out mid-wall.
Compare the price per gallon of the bucket and of single gallons at your store before choosing, because prices vary by store, region and sale. A full bucket is heavy, so plan to pour it into a roller tray or a smaller pail instead of carrying it up a ladder.
Mixing several gallons together (boxing)
Two gallons tinted to the same color on the same day can still differ very slightly. On one wall, a switch from one can to the next can show as a faint line, especially in raking light. Painters avoid this by boxing: pouring all the gallons of one color into a clean 5-gallon bucket and stirring them together before starting. Paint makers demonstrate the same step, mixing two gallons in a 5-gallon bucket for color consistency.
To box paint, stir each can first, pour them into the empty bucket, stir the combined paint thoroughly with a stick or a drill mixer, and scrape the stick back into the bucket. Pour back into the original cans if you need to move the paint, and label them. Box only the same product, sheen and color. If you have only two cans and no bucket, a simpler trick is to finish a whole wall from one can before opening the next, so that any slight difference lands at a corner where it is hard to see.
Worked example
Take a bedroom 12 ft long and 10 ft wide with 8 ft walls, one door and two windows. Gross wall area is 2 × (12 + 10) × 8 = 352 sq ft. Subtract 20 sq ft for the door and 12 sq ft for each window: 352 − 20 − 24 = 308 sq ft of paintable wall.
For two coats at 400 sq ft per gallon, the paint needed is 308 × 2 ÷ 400 = 1.54 gallons, which rounds to 1.5 gallons. The calculator plans that as 1 gallon plus 2 quarts: one whole gallon, and a half-gallon remainder covered by two quarts. Some people round up to a second gallon instead, so that a missed patch or a thirsty wall does not mean another trip to the store, and so that one color comes from as few cans as possible. If the walls are new drywall, the calculator's 0.8 surface factor lowers the effective rate to 320 sq ft per gallon: 308 × 2 ÷ 320 = 1.925, which rounds to 1.9 gallons. The remainder after one gallon is more than half a gallon, so the plan becomes 2 gallons, with very little spare.
If the same room also needs its baseboards and door painted in a contrasting semi-gloss, add one quart for that trim: two coats on about 40 sq ft of trim is roughly 0.2 gallons, which the calculator plans as 1 quart, as the guide to paint sheens works through. Run your own numbers in the paint calculator, and see how many coats of paint you need before deciding on the coat count.