How much paint for a 12x13 room?
At 50 ft around and 364 sq ft of net wall, a 12x13 room needs 2.08 gallons of wall paint for two coats, or 2.29 with the standard 10% waste.
A 12x13 ft room with 8-foot ceilings needs 2.08 gallons of paint for two coats — buy 2 × 1-gallon cans + 2 × quarts. That is 400 sq ft of gross wall, 364 sq ft after deducting one door (21 sq ft) and one window (15 sq ft), covered twice against 350 sq ft per gallon. With the standard 10% waste buffer it comes to 2.29 gallons, about $112 of paint. Having it painted runs about $508 for the walls, or $912 with the ceiling and trim.
Rates and coverage figures updated August 2026. Compiled 2026 from sources last updated 2023–2026.What to actually buy
- 2 × 1-gallon cans + 2 × quarts of wall color — $112, leaving 0.21 gal spare.
- On the walls, rounding up to 3 full gallons instead costs $120 and leaves 0.71 gal you will not use.
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What a 12x13 room is, and what that means for the job
Nobody designs a 12x13. You measure into one. Floor plans are drawn in round numbers and framed houses are not, so the 12x12 bedroom in the listing tapes out at 12 ft by 13 ft, and what you have is a large second bedroom, a guest room or a nursery. Space for a full bed and a dresser, but not space for the bed to sit anywhere except along the long wall.
Round up when you tape, never down. A wall that reads 12 ft 8 in is a 13 ft wall for paint purposes, and the alternative is a second trip to the store in the middle of a coat. The rest is easy at this size. A guest bed, a dresser and a nightstand reach the center of the floor in ten minutes, and closet doors come off their hinges in five. Ceilings in a room like this normally stay as they are, so the whole job is walls, trim, and one long afternoon of cutting in.
The numbers behind the answer
| Ceiling height | Gross wall | Net wall | 1 coat | 2 coats | 2 coats + waste |
|---|---|---|---|---|---|
| 8 ft | 400 | 364 | 1.04 | 2.08 | 2.29 |
| 9 ft | 450 | 414 | 1.18 | 2.37 | 2.60 |
| 10 ft | 500 | 464 | 1.33 | 2.65 | 2.92 |
The arithmetic is worth seeing once: 400 sq ft of gross wall comes from 2 × (12 + 13) × 8 ft. Take off 21 sq ft for the door and 15 for the window and you have 364 sq ft to cover. Two coats is 728 sq ft of coverage, and at 350 sq ft per gallon that is 2.08 gallons. Every figure on this page comes from that one calculation.
No other common room size shares a 50-foot perimeter, so the 12x13 sits on its own in the chart. What it does share is the rule underneath it: wall paint tracks the distance around the room, not the area of the floor. That is why a 12x13 at 156 sq ft of floor needs 2.08 gallons while a room with more floor and a tighter perimeter can need less.
What to buy
Put two gallons and two quarts in the cart, $112. This is the size where one quart almost does it: two gallons plus a quart is 2.25 gallons and the job with waste is 2.29. Four hundredths short is still short, and it shows up on the last wall of the second coat. The second quart is about $16 and ends the question. Three gallons fixes it too, for $8 more and 0.71 gallon left on the shelf.
Painting the ceiling and trim too
| Surface | Area | Paint, 2 coats | Buy |
|---|---|---|---|
| Walls | 364 sq ft net | 2.29 gal | 2 × 1-gallon cans + 2 × quarts |
| Ceiling | 156 sq ft | 0.98 gal | 1 × 1-gallon can |
| Trim and baseboard | 47 linear ft | 0.21 gal | 1 × quart |
What changes the answer
This room sits four hundredths of a gallon above the two-gallons-and-a-quart line, so it has no headroom at all. A 9 ft ceiling puts 50 ft of perimeter under an extra foot of wall: 2.37 gallons, 2.60 with waste, and the quarts turn into a third gallon. Knockdown texture drops coverage from 350 to about 275 sq ft per gallon and lands on 2.64. Even orange peel, the mildest texture in the house, moves 2.08 to 2.24, which the second quart still covers, but only just.
| Change | Paint needed | Effect |
|---|---|---|
| Baseline | 2.08 gal | the figure this page answers with |
| 9 ft ceiling | 2.37 gal | +0.29 gal |
| 10 ft ceiling | 2.65 gal | +0.57 gal |
| Orange-peel texture | 2.24 gal | +0.16 gal |
| Knockdown texture | 2.65 gal | +0.57 gal |
| Three coats | 3.12 gal | +1.04 gal |
| A second window | 1.99 gal | −0.09 gal — an opening removes wall you would have had to cover |
| No window at all | 2.17 gal | +0.09 gal |
Doing it yourself against hiring it out
| Route | What you pay | What it takes |
|---|---|---|
| Do it yourself | $112 of paint, plus roughly $22 of sundries | 2 × 1-gallon cans + 2 × quarts, one weekend |
| Hire it out | $508 for walls only | about 6.7 painter-hours |
| Hire it out, full room | $912 with ceiling and trim | walls, ceiling and 47 ft of trim |
A single room can also fall under a painter's job minimum, which runs $250–$500 whatever the square footage covers — mobilizing a crew costs the same for one room as for five. If you are pricing work rather than buying paint, the painting estimate calculator builds the full line-itemed bid.
A 12x13 room, answered
How much paint for a 12x13 bedroom?
2.08 gallons for two coats, 2.29 with waste. The room is 50 ft around, so 400 sq ft of gross wall at an 8 ft ceiling, and a 21 sq ft door plus a 15 sq ft window leaves 364 sq ft to cover. Two gallons and two quarts, about $112, is the cheapest combination that actually finishes the job. Two flat gallons leaves you just under a third of a gallon short on the second coat.
Is a 12x13 room close enough to 12x12 to use the same paint estimate?
No. One extra foot adds 2 ft of perimeter and 16 sq ft of net wall, 348 up to 364, which moves the requirement from 1.99 to 2.08 gallons. Small as that sounds, it crosses a buy line: a 12x12 finishes on two gallons and one quart at about $96, while a 12x13 needs the second quart and about $112. Measure the room with a tape rather than trusting the listing or the floor plan.
Does a 12x13 room need primer as well as paint?
One gallon of primer, and only if the walls call for it. Primer is a single coat over 364 sq ft, which is 1.04 gallons at 350 sq ft per gallon. You need it on bare drywall, over water or smoke stains, and when you are covering a much darker color. Over an existing painted wall in a similar shade, skip it and put the money into better paint instead.
How much does it cost to paint a 12x13 room?
$112 in paint if you do it, about $508 if a painter does. The materials figure is two gallons and two quarts at $40 a gallon; the bid prices 364 sq ft of wall near $1.40 per sq ft, inside a $1.00 to $3.00 range. A single room can also fall under a $250 to $500 minimum charge, so bundling it with the hallway usually gets you a better rate per room.
Sources and method
Coverage rates come from Sherwin-Williams and Benjamin Moore product data sheets; cost ranges were compiled in August 2026 from HomeGuide and Angi/HomeAdvisor, whose own pages date from 2023 to 2026. Angi owns HomeAdvisor, so those are one source and not two. Quantities on this page assume 350 sq ft per gallon per coat on smooth primed drywall, a 21 sq ft door and a 15 sq ft window; sources put windows anywhere from 10 to 16 sq ft, so change the opening counts in the calculator if yours differ. The full constants are on the paint coverage chart, and the cost basis is set out on interior painting cost per square foot.
This is an estimate for planning, not a quote. Measure your own room before buying.