How much paint do I need for a 12x12 ceiling?

0.41 gallons for one coat and 0.82 for two, at 350 square feet per gallon. Buy 4 quarts or one gallon for two coats. A textured 12 x 12 ceiling needs about 1.03 gallons for two coats.

Will one gallon of paint cover a ceiling?

One gallon covers about 350 square feet with one coat, so it does a ceiling up to about 18 x 19 ft once, or a 12 x 14 ft ceiling twice. A 15 x 15 ft ceiling needs 1.29 gallons for two coats, so buy 2.

How many coats of paint does a ceiling need?

Two is the standard. One coat only works when you are refreshing the same white on a clean, sound ceiling. New drywall, a colour change, patched areas or a ceiling that has yellowed all need two coats to look even under raking light from the windows.

Do textured or popcorn ceilings need more paint?

Yes, plan on 20 to 30% more, because the surface area is larger than the flat area and the roller has to push paint into the texture. The tables use 25%. Use a thick-nap roller, and never soak a popcorn ceiling: the texture can loosen and come off on the roller.

Do I need to prime a ceiling before painting?

Bare drywall or plaster: yes, one coat of primer, counted separately at the coverage printed on the primer can. Water stains and smoke marks need a stain-blocking primer first; extra coats of ordinary paint will not hide them. A previously painted ceiling in good condition does not need primer.

What sheen should I use on a ceiling?

Flat (matte). It hides roller marks, joints and small defects, which show badly on a ceiling because light rakes across it. Kitchens and bathrooms sometimes use a washable flat or eggshell; anything shinier highlights every imperfection.

How much paint do I need for a ceiling?

A 12 x 12 ft ceiling is 144 square feet, so at the 350 square feet per gallon printed on a typical can of flat ceiling paint it takes 0.41 gallons for one coat and 0.82 for two: two quarts for one coat, or one gallon for two coats with a little left. A 20 x 20 ft ceiling needs 3 gallons for two coats. Ceilings have nothing to deduct, so the sums are simpler than for walls.

Open the paint calculator

Ceiling paint by size

Multiply length by width for the area, divide by the coverage on the can, multiply by the coats and round up to whole cans. The table assumes 350 square feet per gallon, a typical figure for flat ceiling paint on a smooth, previously painted ceiling. Quarts are a quarter of a gallon, and often the better buy for a single small ceiling.

Ceilings at 350 sq ft per gallon
Ceiling	Area (sq ft)	One coat (gal)	Buy (quarts)	Two coats (gal)	Buy (quarts)	Buy (gallons)
10 x 10 ft	100	0.29	2	0.57	3	1
10 x 12 ft	120	0.34	2	0.69	3	1
12 x 12 ft	144	0.41	2	0.82	4	1
12 x 14 ft	168	0.48	2	0.96	4	1
12 x 15 ft	180	0.51	3	1.03	5	2
15 x 15 ft	225	0.64	3	1.29	6	2
15 x 20 ft	300	0.86	4	1.71	7	2
20 x 20 ft	400	1.14	5	2.29	10	3

How to calculate paint for any ceiling

Length x width = square feet. Divide by 350 (or the figure on your can) for the gallons per coat, then double it for two coats. An L-shaped or open-plan ceiling is two rectangles added together; the paint calculator takes the area directly, and the room planner gives ceiling area for a whole floor at once. Unlike walls, there are no doors or windows to subtract; only skip the area of a large skylight or a stairwell opening.

Textured and popcorn ceilings use more

Texture roughly doubles the surface the roller has to wet. A quarter more paint is a sensible planning allowance for medium texture; heavy popcorn can take a third more. Use a 3/4 inch nap roller and paint the first coat lightly so the texture does not soften and pull away.

Textured ceilings, two coats, 25% extra
Ceiling	Two coats (gal)	Buy (gallons)
12 x 12 ft	1.03	2
15 x 15 ft	1.61	2
20 x 20 ft	2.86	3

Ceiling paint versus wall paint

Ceiling paint is a flat, usually thicker emulsion made to spatter less overhead and hide imperfections. Ordinary flat wall paint works too and covers about the same area; what does not work is a satin or gloss wall paint, which shows every roller lap once the sun comes through the window. Painting the walls as well? The 12x12 room guide covers them, and there doors and windows do come off the area.

Metric: ceilings in litres

With coverage of 10 m² per litre, as printed on typical European emulsion, a 4 x 4 m ceiling takes 1.6 litres per coat. Cans come in 2.5 and 5 litres.

Ceilings at 10 m² per litre
Ceiling	Area (m²)	One coat (L)	Two coats (L)	2.5 L cans	5 L cans
3 x 3 m	9	0.9	1.8	1	1
3 x 4 m	12	1.2	2.4	1	1
4 x 4 m	16	1.6	3.2	2	1
4 x 5 m	20	2	4	2	1
5 x 5 m	25	2.5	5	2	1
6 x 6 m	36	3.6	7.2	3	2

Before you start

Paint the ceiling before the walls, so drips land on a surface you are about to paint anyway.
Cut in the edges with a brush, then roll in one direction, working away from the main window so laps are lit from behind rather than across.
Coverage on the can assumes a normal film. Pressing a nearly dry roller does not save paint; it leaves a thin coat you will redo.
For the whole room in one go, see how many square feet a gallon of paint covers on the walls.

Frequently asked questions

How much paint do I need for a 12x12 ceiling?: 0.41 gallons for one coat and 0.82 for two, at 350 square feet per gallon. Buy 4 quarts or one gallon for two coats. A textured 12 x 12 ceiling needs about 1.03 gallons for two coats.
Will one gallon of paint cover a ceiling?: One gallon covers about 350 square feet with one coat, so it does a ceiling up to about 18 x 19 ft once, or a 12 x 14 ft ceiling twice. A 15 x 15 ft ceiling needs 1.29 gallons for two coats, so buy 2.
How many coats of paint does a ceiling need?: Two is the standard. One coat only works when you are refreshing the same white on a clean, sound ceiling. New drywall, a colour change, patched areas or a ceiling that has yellowed all need two coats to look even under raking light from the windows.
Do textured or popcorn ceilings need more paint?: Yes, plan on 20 to 30% more, because the surface area is larger than the flat area and the roller has to push paint into the texture. The tables use 25%. Use a thick-nap roller, and never soak a popcorn ceiling: the texture can loosen and come off on the roller.
Do I need to prime a ceiling before painting?: Bare drywall or plaster: yes, one coat of primer, counted separately at the coverage printed on the primer can. Water stains and smoke marks need a stain-blocking primer first; extra coats of ordinary paint will not hide them. A previously painted ceiling in good condition does not need primer.
What sheen should I use on a ceiling?: Flat (matte). It hides roller marks, joints and small defects, which show badly on a ceiling because light rakes across it. Kitchens and bathrooms sometimes use a washable flat or eggshell; anything shinier highlights every imperfection.

How much paint do I need for a 12x12 room?
Gallons of paint for a 12 x 12 ft room with 8, 9 or 10 ft ceilings, one or two coats, a door and two windows deducted, plus the 4 x 4 m room in litres.
How many square feet does a gallon of paint cover?
A gallon covers about 350 to 400 sq ft on smooth walls, less on rough or bare surfaces. Gallons for 400 to 2,000 sq ft at one and two coats, and litres per square metre.
How much paint for a 10x10 room? (10x12, 12x14 and 14x16 too)
Gallons of paint for a 10x10 room with an 8 ft ceiling, a door and two windows, one or two coats, plus the ceiling; 10x12 to 14x16 rooms; 3x3 to 4x5 m rooms in litres.
How many square feet does a quart of paint cover?
A quart covers about 90 to 100 sq ft with one coat: what that means for a door, a wall, trim and a small ceiling at one and two coats, plus litres and 5 gallon pails.

Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.