How Much Paint for a 12×12 Room?
Quick Answer
A 12×12 foot room with 8-foot ceilings has approximately 330 square feet of paintable wall area. You need about 2 gallons of paint for two coats.
- Paintable wall area: ~330 sq ft (after subtracting door & windows)
- 1 coat: ~1 gallon
- 2 coats (recommended): ~2 gallons
- Ceiling (if painting): add 1 gallon of ceiling paint
Formula
Perimeter times ceiling height gives gross wall area. Subtract doors (~21 sq ft each) and windows (~15 sq ft each). Multiply by number of coats, then divide by 350 sq ft per gallon.
Step-by-Step Calculation
- 1
Room perimeter
(12 + 12 + 12 + 12) = 48 feet
- 2
Gross wall area
48 × 8 = 384 sq ft
- 3
Subtract openings
384 − 21 (door) − 30 (2 windows) = 333 sq ft
- 4
Two coats
333 × 2 = 666 sq ft of coverage needed
- 5
Gallons
666 ÷ 350 = 1.9 → 2 gallons
Paint Needed by Room Size (2 Coats, 8-ft Ceiling)
| Room Size | Wall Area* | Gallons (2 Coats) | Ceiling Gallon | Est. Cost** |
|---|---|---|---|---|
| 10×10 ft | 270 sq ft | 1.5 → 2 gal | 1 gal | $60–$140 |
| 10×12 ft | 300 sq ft | 1.7 → 2 gal | 1 gal | $60–$140 |
| 12×12 ft | 330 sq ft | 1.9 → 2 gal | 1 gal | $60–$140 |
| 12×14 ft | 360 sq ft | 2.1 → 3 gal | 1 gal | $80–$210 |
| 14×16 ft | 415 sq ft | 2.4 → 3 gal | 1–2 gal | $80–$210 |
*After subtracting 1 door + 2 windows. **At $30–$70 per gallon depending on paint quality.
Frequently Asked Questions
Do I need primer for a 12×12 room?
Use primer if painting over a dark color, on new drywall, or on stained surfaces. Self-priming paints (paint + primer in one) work well for same-color refreshes or light color changes, saving one coat.
How long does it take to paint a 12×12 room?
A DIYer can paint a 12×12 room in 4–6 hours (2 coats with drying time between). Prep work (taping, patching, covering) adds 1–2 hours. Professional painters can complete it in 2–3 hours.
Should I buy 1 gallon or 5 gallons?
For a single 12×12 room, 2 gallons is perfect. If painting multiple rooms the same color, a 5-gallon bucket is 15–25% cheaper per gallon and ensures consistent color across rooms.