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 a tool used to quickly calculate measurements, conversions, and estimates so you can plan materials and project decisions 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.