How much paint for a 12×12 room?
A 12 × 12 ft room with 8 ft walls needs about 1.91 gallons of paint for two coats, so buy 2 gallons. That is 334 square feet of wall after one door and two windows, at 350 square feet per gallon.
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
- 334 sq ft × 2 coats ÷ 350 sq ft/gal = 1.91 gal
- Buy 2 gallons (2 cans of the size chosen)
A 12 × 12 ft room is the classic primary bedroom or home office, and it is the size where two gallons is the honest answer: one gallon covers barely half of the second coat. The numbers below use 8 ft walls and the low end of the usual coverage range, so a good paint on smooth walls will leave you a little over.
Adjust for your project
More options: Door · Window · Skip …
- Paint needed
- 1.91 gal (7.22 L)
- Wall paint, cans of the size you chose
- 2 cans · 1-gallon
- Area painted (one coat)
- 334 sq ft
- Paint per coat
- 0.95 gal
- Coverage used
- 350 sq ft/gal
- 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 | 334 sq ft | 1.91 gal | 2 gallons |
| 9 ft | 382 sq ft | 2.18 gal | 2 gallons + 1 quart |
| 10 ft | 430 sq ft | 2.46 gal | 2 gallons + 2 quarts |
| 12 ft | 526 sq ft | 3.01 gal | 3 gallons + 1 quart |
What to know about painting a 12×12 room
- The wall area. Four 12 ft walls at 8 ft tall are 384 sq ft. A 36 × 80 in door takes off 20 sq ft and two 3 × 5 ft windows another 30, which leaves 334 sq ft per coat, or 668 sq ft for two.
- Two gallons, not three. 668 ÷ 350 is 1.91 gallons. If your can says 400 sq ft per gallon, it is 1.67 gallons and the second gallon comes home a third full; that leftover is your touch-up stock.
- Closets count. A reach-in closet with its own walls adds roughly 60–80 sq ft; a walk-in can add 150. Paint it the same color and it may push the order to 2 gallons and a quart.
- Higher ceilings. With 9 ft walls the room has 432 sq ft of gross wall, 382 after openings, and two coats come to about 2.2 gallons. Buy 2 gallons and a quart rather than a third gallon.
If you are painting the ceiling at the same time, see how much paint for a 12x12 room and ceiling, or price the ceiling on its own with how much paint for a 12x12 ceiling. New drywall in this room also needs primer first: how much primer for a 12x12 room.
Different size? Use the full Room Paint Calculator.
What you’ll need
- Paint roller frame and covers (9 in)Budget price
A sturdy 9 in frame and a few 3/8 in nap covers handle smooth drywall. Rougher walls and ceilings want 1/2–3/4 in nap, as the data sheets suggest.
See options on Amazon (opens in a new tab) - Angled sash brush (2–2½ in)Budget price
For cutting in along ceilings, corners and trim. A nylon-polyester brush is what the latex data sheets recommend.
See options on Amazon (opens in a new tab) - Painter’s tape (multi-surface)Budget price
Masks trim, ceilings and glass. Pull it at an angle while the last coat is still slightly soft for the cleanest line.
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 with 9 ft ceilings?
About 2.18 gallons for two coats; buy 2 gallons + 1 quart.
How much paint for a 12x12 room with one coat?
About 0.95 gallons, so one gallon covers it if you are repainting a similar color.
How much paint for a 12x12 room at 400 sq ft per gallon?
About 1.67 gallons for two coats. You still buy 2 gallons, with more left over.
Other common sizes
- 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 much paint for a 12x12 room and ceiling — 1.91 gal walls + 0.82 gal ceiling, 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.