How much paint for a 12×15 room with 9' ceilings?
Answer
3 gallons (2 coats)
Total wall area: 486 sq ftPaintable area (after openings): 413 sq ftCoverage needed (2 coats): 826 sq ft
Need a custom calculation?
Open the full calculator with custom inputs
How We Calculated This
Gallons = (Paintable Wall Area × Coats) / 350 sq ft per gallon
Walls: 2 × (15 + 12) × 9 = 486 sq ft. After 15% openings: 413 sq ft. × 2 coats = 826 sq ft ÷ 350 = 3 gallons
Related Calculations
How much paint for a 8×8 room with 8' ceilings?2 gallons (2 coats)How much paint for a 8×8 room with 9' ceilings?2 gallons (2 coats)How much paint for a 8×8 room with 10' ceilings?2 gallons (2 coats)How much paint for a 8×8 room with 12' ceilings?2 gallons (2 coats)How much paint for a 8×10 room with 8' ceilings?2 gallons (2 coats)
Calculated using verified formulas. Last updated March 2026.