How Much Paint for a 12x15 Room?
A 12×15 ft room with 8 ft ceilings has 382 sq ft of paintable wall. Two coats take 2.18 gallons, so buy 3 gallons of wall paint. Adding the ceiling brings the total to 3.21 gallons (4 gallons).
Paint needed for a 12x15 room
| Scenario | Paintable area | Exact gallons | Buy |
|---|---|---|---|
| Walls, 1 coat | 382 sq ft | 1.09 | 2 gallons |
| Walls, 2 coats | 382 sq ft | 2.18 | 3 gallons |
| Ceiling, 2 coats | 180 sq ft | 1.03 | 2 gallons |
| Walls + ceiling, 2 coats | 562 sq ft | 3.21 | 4 gallons |
| Walls, 2 coats, 9 ft ceiling | 436 sq ft | 2.49 | 3 gallons |
Assumes 1 door (20 sq ft) and 2 windows (15 sq ft each) deducted, 350 sq ft per gallon, 8 ft ceiling unless stated. Trim and doors not included.
How it is calculated
Walls: 2 × (12 + 15) × 8 = 432 sq ft
Minus door and windows: 432 − 50 = 382 sq ft
Two coats: 382 × 2 ÷ 350 = 2.18 gallons → 3 gallons
Ceiling: 12 × 15 = 180 sq ft → 180 × 2 ÷ 350 = 1.03 gallons
Tips for a 12x15 room
- You need 2.18 gallons, so 3 gallons leaves about 3.3 quarts spare – enough for touch-ups. Do not bother with a 5-gallon bucket.
- Cutting in with a brush runs 54 ft along the ceiling line and another 54 ft along the baseboards, before counting door and window frames.
- The 180 sq ft ceiling needs only 1.03 gallons for two coats, so a quart or a gallon of ceiling paint is plenty.
Frequently asked questions
How many gallons of paint for a 12x15 room?
With 8 ft ceilings the walls total 2 × (12 + 15) × 8 = 432 sq ft. After deducting 50 sq ft for one door and two windows, 382 sq ft remain. Two coats at 350 sq ft per gallon is 2.18 gallons, so buy 3 gallons. One coat needs 1.09 gallons.
How much paint for the walls and ceiling of a 12x15 room?
The ceiling adds 180 sq ft. Walls plus ceiling, two coats, comes to 3.21 gallons, so buy 4 gallons. The ceiling alone needs 1.03 gallons for two coats.
How much does it cost to paint a 12x15 room?
Paint for the walls (3 gallons) costs roughly $75–$180 at $25–$60 per gallon. With 9 ft ceilings you would need 2.49 gallons, so 3 gallons. Primer, tape and supplies are extra.