Paint Coverage Room
Calculator
Results
- Paint
- 6.363636
Home and garden results
| Paint | 6.363636 |
formula-map diagram
- Paint
- 6.363636
Home and garden relationship
Formula
L = (P × h − openings) × coats ÷ spread= 6.3636363636364
Note
This result uses the values you entered and a simplified planning equation; verify quantities and local requirements before purchasing or building.
More in Home and garden
See all →Frequently asked questions
How does the calculator turn room dimensions into gallons of paint?+
It calculates total wall area (perimeter times height), subtracts doors and windows, then divides by the paint's coverage rate, typically 350-400 square feet per gallon, to determine how many gallons you need per coat.
Why does the calculator ask how many coats I'm applying?+
Most paint jobs need two coats for even, opaque color, especially over a different existing color or bare drywall, so the gallon total essentially doubles between one coat and two. Skipping this step is the most common reason people run short mid-project.
Should I subtract the full window and door area from my wall total?+
Yes, standard doors (about 20 sq ft) and average windows (about 15 sq ft) don't get paint, so leaving them in the calculation overestimates how much paint you need. For rooms with many openings, this can change the total by half a gallon or more.
Does ceiling color count toward the same paint total as the walls?+
No, ceilings are almost always calculated separately since they typically use a different paint (flat white ceiling paint) even when using the same coverage-rate math: ceiling area divided by the coverage rate per gallon.
Why did I still run out of paint even though the math said I had enough?+
Textured walls, porous new drywall, and darker colors covering lighter ones all reduce actual coverage below the can's stated rate, sometimes to 250-300 square feet per gallon. Buying one extra quart as a buffer avoids an emergency store run mid-coat.