PAINT PLANNING
How much paint do you need for a 12x12 room?
For a 12-by-12-foot room with 8-foot walls, the four walls total 384 square feet before subtracting doors and windows. The exact gallons depend on openings, number of coats, and the coverage listed on your paint.
Quick 12x12 example
A 12x12 room has a 48-foot perimeter. At an 8-foot wall height, 48 × 8 gives 384 square feet of wall area. If doors and windows account for about 40 square feet, the paintable wall area is about 344 square feet.
With two coats, that becomes about 688 square feet of coverage. At 350 square feet per gallon, the math is 688 ÷ 350 = 1.97 gallons. In practical terms, you would plan on 2 gallons for the walls in this example.
Why your room may need more or less
- Taller ceilings increase wall area.
- A second coat roughly doubles the coverage requirement.
- Large doors and windows reduce paintable wall area.
- Coverage varies by paint product and surface condition.
- Ceilings, trim, doors, and accent walls should be estimated separately when they use different paint.
Use your actual measurements
The 2-gallon example is useful for planning, but your own room dimensions are better. Enter the room length, width, wall height, openings, coats, and paint coverage into the calculator for a project-specific estimate.