How much paint for a 12×12 room and ceiling?
Walls and ceiling of a 12 × 12 ft room with 8 ft walls need about 2.73 gallons for two coats: 1.91 gallons for the walls and 0.82 gallons for the ceiling.
How to work it out
- 2 × (12 ft + 12 ft) × 8 ft = 384 sq ft of wall − 1 door × 20 sq ft − 2 windows × 15 sq ft = 334 sq ft
- + ceiling 144 sq ft = 478 sq ft
- 478 sq ft × 2 coats ÷ 350 sq ft/gal = 2.73 gal
- Walls 1.91 gal, ceiling 0.82 gal → buy 2 gallons wall paint + 1 gallon ceiling paint
Painting the ceiling at the same time adds 144 sq ft to a 12 × 12 room, about 40% more surface than the walls alone. Most people use a flat ceiling paint up top and a wall paint below, so the useful answer is the split: what each part takes.
Adjust for your project
More options: Door · Window · Skip …
- Paint needed
- 2.73 gal (10.3 L)
- Wall paint, cans of the size you chose
- 2 cans · 1-gallon
- Area painted (one coat)
- 478 sq ft
- Paint per coat
- 1.37 gal
- Coverage used
- 350 sq ft/gal
- Ceiling paint, cans of the size you chose
- 1 can · 1-gallon
- Of which walls
- 1.91 gal
- Of which ceiling
- 0.82 gal
- Walls and ceiling are bought as two products, each rounded up on its own. If you also save this ceiling from the ceiling paint calculator, the project list will count it twice.
- Coverage is per coat on a smooth, primed wall. Fresh drywall, flat old paint and textured walls soak up more, so if you are near a can boundary, round up.
- Old house? If it was built before 1978, read lead paint safety before you sand or scrape: EPA advises assuming old paint contains lead until it is tested.
Paint for this room by wall height
| Wall height | Area painted (one coat) | Paint needed | Buy (gallons and quarts) |
|---|---|---|---|
| 8 ft | 478 sq ft | 2.73 gal | 2 gallons wall paint + 1 gallon ceiling paint |
| 9 ft | 526 sq ft | 3.01 gal | 2 gallons + 1 quart wall paint + 1 gallon ceiling paint |
| 10 ft | 574 sq ft | 3.28 gal | 2 gallons + 2 quarts wall paint + 1 gallon ceiling paint |
| 12 ft | 670 sq ft | 3.83 gal | 3 gallons + 1 quart wall paint + 1 gallon ceiling paint |
Walls and ceiling: what to buy
- Walls: 2 gallons. 334 sq ft after the door and windows, two coats, 1.91 gallons at 350 sq ft per gallon.
- Ceiling: 1 gallon. 144 sq ft, two coats, 0.82 gallons. A flat ceiling paint on a smooth ceiling usually covers in two coats; a textured or popcorn ceiling drinks more and is better planned at 250 sq ft per gallon, which makes it about 1.15 gallons.
- All one color? If walls and ceiling are the same paint, the total is 2.73 gallons: buy three gallons and box them together.
- Order of work. Ceiling first, then walls, then trim. Drips from the ceiling land on walls you haven’t painted yet.
Ceiling paint is formulated to spatter less and dry dead flat, which hides roller marks when light rakes across it from a window. The Behr ceiling paint data sheet, for instance, gives 250–400 sq ft per gallon and calls out textured and popcorn ceilings specifically. The ceiling on its own is worked out on how much paint for a 12x12 ceiling, and the walls alone on how much paint for a 12x12 room.
Different size? Use the full Room Paint Calculator.
What you’ll need
- Extension pole (4–8 ft)Budget price
Rolls ceilings and tall walls from the floor, with more even pressure than reaching from a ladder.
See options on Amazon (opens in a new tab) - Roller covers, 3/8 in and 1/2 in napBudget price
Shorter nap for smooth walls and trim-adjacent work, longer nap for textured ceilings and rough siding. A fresh cover per color saves cleanup.
See options on Amazon (opens in a new tab) - Canvas drop clothBudget price
Canvas stays put and soaks up drips; plastic is cheaper but slippery underfoot and spreads wet paint.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How much paint for a 12x12 room and ceiling with one coat?
With one coat everywhere it is about 1.37 gallons; most people still give the walls two.
How much paint for a 10x10 room and ceiling?
About 2.11 gallons for two coats: 1.54 gallons walls and 0.57 gallons ceiling.
Other common sizes
- How much paint for a 12x12 room — 1.91 gal: buy 2 gallons (walls only, 2 coats)
- How much paint for a 10x10 room — 1.54 gal: buy 2 gallons (walls only, 2 coats)
- How much paint for a 10x12 room — 1.73 gal: buy 2 gallons (walls only, 2 coats)
- How much paint for a 12x14 room — 2.09 gal: buy 2 gallons + 1 quart (walls only, 2 coats)
- How much paint for a small bathroom — 0.73 gal: buy 1 gallon (walls only, 2 coats)
- How many litres of paint for a 10x12 room — 6.52 L: 1 × 5 L + 2 × 1 L (walls, 2 coats)
Sources
- Sherwin-Williams, ProMar 200 Zero VOC Interior Latex Eg-Shel (B20 series), product data sheet (opens in a new tab) — Coverage 350–400 sq ft per gallon at 4 mils wet; two coats over primer on drywall; sheen 15–20 units at 85°.
- Sherwin-Williams, ProMar 200 Zero VOC Interior Latex Flat (B30 series), product data sheet (opens in a new tab) — Coverage 350–400 sq ft per gallon at 4 mils wet; sheen 1.5–3.5 units at 85°.
- Benjamin Moore, Regal Select Interior Eggshell (549), technical data sheet (opens in a new tab) — Coverage 400–450 sq ft per gallon at 3.8 mils wet; two coats for full color; eggshell 15–22 units at 85°.
- Behr, Premium Plus Interior Flat Paint (No. 1050), technical data sheet (opens in a new tab) — Coverage 250–400 sq ft per gallon depending on application method and substrate porosity; does not include spray loss.
- US EPA, Lead Renovation, Repair and Painting Program Rules (opens in a new tab) — Covers homes, child care facilities and kindergartens built before 1978; firms and renovators must be certified.