Drywall Calculator – How Many Sheets Do I Need? | CalcLoft
Find out exactly how many drywall sheets you need, plus screws and joint compound.
How to estimate drywall
Add the wall area (perimeter × height) and the ceiling area (length × width). For a 12 × 12 ft room with 8 ft ceilings: walls = 48 × 8 = 384 sq ft, ceiling = 144 sq ft, total ≈ 528 sq ft. Add 10% waste for cuts around doors and windows: about 580 sq ft → 19 sheets of 4×8 (32 sq ft each).
Sheets needed quick reference
| Room | 4×8 sheets (walls + ceiling) |
|---|---|
| 10×10 bedroom | ~15 sheets |
| 12×12 bedroom | ~19 sheets |
| 12×14 bedroom | ~21 sheets |
| 14×16 master | ~25 sheets |
Don't forget supplies
For every 10 sheets, plan roughly: 1 box of drywall screws (1 lb), 1-2 rolls of tape, and one 25 lb bag of joint compound per 4-5 sheets.
Drywall calculator FAQ
Do I need to count doors and windows?
Our waste allowance covers the cuts around openings. If your room has large windows or many openings, choose 15% waste.
4x8 or 4x12 sheets?
4×8 is standard and fits through most doorways. 4×12 reduces seams on tall walls but is heavier and harder to handle solo.
Is 1/2 inch or 5/8 inch better?
1/2 inch is standard for walls. 5/8 inch is required for ceilings in many codes (fire-rated) and is stiffer.
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