Enter room dimensions and ceiling height to get wall area, room volume, paint gallons, and drywall sheets — everything for planning walls, not just floors.
The Square Footage with Ceiling Height Calculator is used to quickly calculate key measurements and estimates so you can plan materials, costs, and project scope with confidence.
Measure room length and width. Perimeter = 2 × (Length + Width). For a 14 × 12 ft room: 2 × (14 + 12) = 52 linear feet.
Gross wall area = Perimeter × Ceiling height. 52 × 8 = 416 ft² of wall surface.
Window ≈ 15 ft². Door ≈ 21 ft². 2 windows + 1 door = 51 ft². Net wall area = 416 - 51 = 365 ft².
Paint: 365 ft² ÷ 400 = 0.91 gallons per coat → 2 gallons for 2 coats. Drywall: 416 ft² ÷ 32 + 10% = 14 sheets.
| Room (ft) | Wall Area | Paint (gal, 2 coats) | Drywall (sheets) |
|---|
Perimeter × ceiling height. 2(L+W) × H. Subtract ~15 ft² per window and ~21 ft² per door.
1 gallon covers ~350-400 ft². Divide net wall area by 400 × 2 coats. Round up to nearest gallon.
Floor area × ceiling height. A 200 ft² room with 9 ft ceiling = 1,800 ft³.
8 ft in most homes. 9-10 ft in newer construction. 12+ ft for vaulted ceilings.
Gross wall area ÷ 32 (4×8 sheet size) + 10% waste.