How Much Paint Do I Need for a 12x12 Room? (2026 Guide)
How much paint for a 12x12 room? The answer is 2 gallons for two coats. Step-by-step math, a chart for every room size and buying tips.
Why 12x12 is the most-asked paint question
A 12×12 bedroom is the most common room size in American homes — and the first project most DIYers try. The math is simple once you know it, but most people either buy one gallon too many or run out at the last coat.
The paint math, step by step
1. Measure the wall area
Walls of a 12×12 room: (12 + 12) × 2 × 8 = 384 sq ft.
2. Subtract doors and windows
A standard door is about 21 sq ft; a standard window about 12 sq ft. With one of each: 384 − 21 − 12 = 351 sq ft.
3. Multiply by coats
Two coats: 351 × 2 = 702 sq ft.
4. Divide by coverage
One gallon covers about 350 sq ft on smooth primed drywall. 702 ÷ 350 = 2.0 gallons → buy 2 gallons (or 2 gallons + a quart for touch-ups).
Paint needed for common room sizes
| Room | Wall area | Gallons (2 coats) |
|---|---|---|
| 10×10 | ~300 sq ft | 2 gallons |
| 12×12 | ~351 sq ft | 2 gallons |
| 12×14 | ~395 sq ft | 2-3 gallons |
| 14×16 | ~490 sq ft | 3 gallons |
| 12×20 living room | ~510 sq ft | 3 gallons |
When you need more paint
- Textured walls — coverage drops to 250-300 sq ft/gallon
- Unprimed drywall — absorbs more, plan 3 coats for deep colors
- Dark color changes — priming first can save a coat
Final tip
Always buy 10% extra and keep the leftover can labeled. Touch-ups after a year will never match unless you have the original color mixed at the store.
FAQ
How many gallons for a 12x12 room with 10 ft ceilings?
Walls become (12+12)×2×10 = 480 sq ft. With one door and window and two coats, you need about 2.5-3 gallons.
Does one gallon cover a 12x12 room?
One gallon covers about 350 sq ft — not enough for two coats on a 12×12 room (~700 sq ft). You need 2 gallons for proper coverage.
Should I include the ceiling?
Ceilings need their own paint (usually one coat of ceiling paint). Add ~144 sq ft for a 12×12 ceiling if painting it.
Need a different size?
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