How much paint for a 12x18 room?
A 12x18 ft room has about 444 sq ft of wall after subtracting one door and one window. For two coats you need roughly 2.5 gallons.
For 2 coats, walls, 8 ft ceiling
2.5 gallons (~3 cans)
About 444 sq ft of paintable wall.
Calculate your exact amount
Adjust the height, coats, doors and windows for your room:
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Paint needed for a 12x18 room (chart)
| Ceiling height | 1 coat | 2 coats | 3 coats |
|---|---|---|---|
| 8 ft | 1.3 gal | 2.5 gal | 3.8 gal |
| 9 ft | 1.4 gal | 2.9 gal | 4.3 gal |
| 10 ft | 1.6 gal | 3.2 gal | 4.8 gal |
Based on ~350 sq ft per gallon per coat, minus one door and one window.
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Shop interior paint →How we calculated this
- Wall area = 2 × (length + width) × height = 2 × (12 + 18) × 8 = 480 sq ft.
- Minus one door (21 sq ft) and one window (15 sq ft) = 444 sq ft.
- × 2 coats ÷ 350 sq ft per gallon = 2.5 gallons.
Frequently asked questions
- How many gallons of paint for a 12x18 room?
- About 2.5 gallons for two coats of walls with 8 ft ceilings, or 1.3 gallons for a single coat.
- How much paint do I need for a 12x18 room with high ceilings?
- Use the chart above — a 10 ft ceiling raises it to about 3.2 gallons for two coats.