How much paint do I need for a 12x12 room?
Paint quantity for a standard 12-foot by 12-foot bedroom
A 12x12 room with 8-foot walls needs about 2 gallons of wall paint for two coats once you subtract a standard door and window.
The numbers below assume the inputs in the assumptions section. Change any of them in the calculator to fit your own project.
A 12-foot by 12-foot room is one of the most common sizes people paint, so it is a useful anchor for an estimate. The number that matters is wall area, not floor area, and that depends on ceiling height plus how many doors and windows break up the walls.
This page walks through the math for a typical 8-foot ceiling, then lets you change the numbers for your own room. If your ceiling is taller, your walls have extra openings, or you are painting the ceiling too, the calculator handles those cases without you redoing the arithmetic by hand.
Prefer the full version with the explanation and examples? Open the calculator page directly.
Open the paint calculatorFour walls, each 12 ft wide.
Standard for most homes; raise this for vaulted ceilings.
Two coats is normal over a similar color; bare or dark walls may need more.
Typical for interior latex paint on a smooth, primed wall.
About 21 sq ft of door and 15 sq ft of window removed from the wall area.
Two coats on the walls of a 12x12 bedroom with one door and one window
- 1Find the gross wall area: 48 ft perimeter x 8 ft height = 384 sq ft.
- 2Subtract the openings: 384 - 21 (door) - 15 (window) = 348 sq ft of paintable wall.
- 3Multiply by coats: 348 sq ft x 2 = 696 sq ft of coverage needed.
- 4Divide by the coverage rate: 696 / 350 = 1.99 gallons.
Buying two 1-gallon cans (or one 2-gallon supply) covers the walls with a little left for touch-ups. Add roughly another half gallon if you are painting the 144 sq ft ceiling as well.
- Estimating from floor area instead of wall area. A 144 sq ft floor has far more than 144 sq ft of wall to cover.
- Forgetting the second coat. One coat rarely hides the old color evenly, so plan for two unless you are repainting the same shade.
- Skipping the openings on a small room while keeping them on a large one. Be consistent, or just leave the doors and windows in for a small safety margin.
- Ignoring primer on bare drywall or a big color change. Primer is a separate coat and changes how much finish paint you need.
How many gallons of paint for a 12x12 room?
About 2 gallons covers the walls of a 12x12 room with an 8-foot ceiling for two coats, after subtracting a standard door and window. Add roughly half a gallon more if you are also painting the ceiling.
Does a 12x12 room with high ceilings need more paint?
Yes. Wall area scales with ceiling height, so a 10-foot ceiling adds about 96 sq ft of wall versus an 8-foot ceiling. Enter your real ceiling height in the calculator to see the difference.
Should I include the ceiling in the estimate?
Only if you plan to paint it. A 12x12 ceiling is 144 sq ft, which needs roughly half a gallon for two coats. The walls and ceiling are usually different paint, so estimate them separately.
How much paint do I need for one coat instead of two?
Halve the two-coat figure: about 1 gallon covers the walls of a 12x12 room for a single coat. Most repaints still need two coats for even coverage unless you are matching the existing color.
What coverage rate should I use?
Around 350 square feet per gallon is typical for interior latex on smooth, primed walls. Textured or porous surfaces cover less, so check the can and lower the rate if your walls are rough.