Standard door & window area deductions
Typical published planning values — NOT a certified spec or professional advice. Coverage and coats vary by product, surface, texture and color; confirm on the paint can’s stated spread rate and the manufacturer’s data. Surface prep, moisture/adhesion and pre-1978 lead paint are a pro’s call — follow the EPA RRP rule and hire a certified firm; lead-paint abatement, structural repairs and code certification are not engineered here.
Net paintable wall area is the gross wall (perimeter × height) minus the openings. These are the labeled standard deductions — a standard interior door about 21 sq ft (3 × 7), a window about 15 sq ft, a patio / sliding-glass door about 40 sq ft — a planning convention you should adjust to your actual openings. Use them with the room paint calculator and the how-much-paint calculator.
| Opening | Deduct (sq ft) |
|---|---|
| Standard interior door (3 × 7) | 21 |
| Standard window | 15 |
| Patio / sliding-glass door | 40 |
labeled planning typicals — measure your actual openings. Deduct doors and windows from the gross wall to get the net paintable area; small windows and trimmed openings vary.