How Much Paint for a 12x12 Room?
Paint needed
2 gallons
A 12 by 12 room with eight foot walls, one door, two windows, two coats.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Room perimeter, add all walls48 ft
- Wall height8 ft
- Doors1
- Windows2
- Coats2
- Coverage per gallon350 sq ft
Paint needed2 gallons
| Gross wall area | 384 sq ft |
|---|---|
| Less doors and windows | -51 sq ft |
| Net wall area | 333 sq ft |
| Area over 2 coats | 666 sq ft |
| Gallons, exact | 1.9 |
| Buy | 2 gallonsor 1 five gallon pail |
The material list this produces
| Paint, gallons | 2 |
|---|---|
| Primer, gallons (if bare or color change) | 1 |
| Painter's tape, rolls | 1 |
Coats compared
Coats is the input people get wrong, usually by hoping. Same room, one coat to three.
| Coats | Paint needed |
|---|---|
| 1 coat | 1 gallon |
| 2 coats | 2 gallons |
| 3 coats | 3 gallons |
What else matters here
Forty eight feet of perimeter by eight feet high is 384 square feet gross, and 333 net after a door and two windows. Two coats is 666 square feet, which lands almost exactly on two gallons at standard coverage. This is the room the two gallon rule of thumb comes from.
The rule breaks the moment anything is unusual. Nine foot ceilings add 48 square feet per coat. A deep or saturated color drops coverage from 350 to nearer 300 and can want three coats rather than two. Textured walls eat noticeably more than smooth ones.
Ceilings are not in this figure. A 12 by 12 ceiling is 144 square feet, so one coat is half a gallon and two coats is most of one. Run it as its own area rather than hoping the wall paint stretches.
What this calculator assumes
- A door is taken as 21 sq ft and a window as 15 sq ft. Deducting them matters on a small room and barely moves a big one.
- 350 sq ft per gallon is the usual figure on a smooth primed wall. Bare drywall, textured walls and deep color changes all drink more, so drop it to 300 if any of those apply.
- Ceilings and trim are not included. Run the ceiling as its own area.
Questions people ask
How many gallons of paint for a 12x12 room?
Two gallons for two coats on eight foot walls. Add a third if the ceilings are nine feet, the color is deep, or the walls are textured.
How much paint for a 12x12 ceiling?
About half a gallon per coat, so one gallon covers two coats with a little left. Ceiling paint is a different product from wall paint and is worth buying as such.
Is 2 coats enough?
Over the same or a similar color on primed walls, yes. Over bare drywall, over a dark color, or with a deep saturated pigment, plan on primer plus two, or three coats of finish.
The paint calculator takes any dimensions you like and hands back the same list.