Paint coverage — sq ft per gallon per coat
Interior paint typically covers ~350–400 sq ft per gallon per coat (the calculators default to 375). It is a labeled planning band — porous or dark-to-light surfaces use more. The table shows two-coat gallons for common rooms; compute yours with the painting cost calculator.
| Room (ft) | Wall area @ 8 ft | 2-coat gallons (@ 375) |
|---|---|---|
| 10×10 | 320 sq ft | 2 gal |
| 12×12 | 384 sq ft | 3 gal |
| 12×15 | 432 sq ft | 3 gal |
| 15×20 | 560 sq ft | 3 gal |
| 20×24 | 704 sq ft | 4 gal |
~350–400 sq ft/gal/coat is a labeled planning band; before subtracting doors/windows. Gallons = ceil(wall area × coats ÷ coverage).