Drywall Calculator
Sheet count for a room: walls are the perimeter times the ceiling height, plus the ceiling if you are doing it. Openings are not subtracted — the cut-outs roughly equal the waste around them. Mud, tape and screws are figured from the same square footage.
Order 19 sheets — use 4 × 12 sheets on long walls to cut the number of butt joints.
- Wall + ceiling area
- 528 ft²
- Waste / cuts 10%
- + 53 ft²
- Coverage to buy
- 581 ft²
- Metric
- 49.1 m²
- 4 × 8 ft sheets (32 ft²)
- 19
- 4 × 12 ft sheets (48 ft²)
- 13
- Approx. weight
- 1,026 lb
- Joint compound, 4.5 gal bucket
- 2 buckets
- Paper tape, 250 ft roll
- 1 rolls
- Drywall screws 1¼″, lb
- 2 lb
- Corner bead, 8 ft
- 2 pcs
- Materials + delivery$12–$22 / sheet · Sep 2026
- $303 – $493
- Installed (with labor)typ. $1,567
- $1,095 – $2,341
- Drywall, ½″ × 4×819 sheets
- Joint compound, 4.5 gal2 buckets
- Paper tape, 250 ft1 rolls
- Drywall screws, 1¼″2 lb
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What will this drywall job cost?
See the installed price range for these quantities and get up to 3 quotes from local contractors. Free, no obligation.
Common room sizes, answered
- How Much Drywall for a 8×10 Room?80 ft²
- How Much Drywall for a 10×10 Room?100 ft²
- How Much Drywall for a 10×12 Room?120 ft²
- How Much Drywall for a 12×12 Room?144 ft²
- How Much Drywall for a 12×14 Room?168 ft²
- How Much Drywall for a 12×16 Room?192 ft²
- How Much Drywall for a 14×16 Room?224 ft²
- How Much Drywall for a 15×15 Room?225 ft²
- How Much Drywall for a 16×20 Room?320 ft²
- How Much Drywall for a 20×20 Room?400 ft²
- How Much Drywall for a 24×24 Room?576 ft²
- How Much Drywall for a 30×40 Room?1200 ft²
How to calculate drywall by hand
Area = 2 × (L + W) × H + L × W (ceiling) · Sheets = area × (1 + waste) ÷ 32
Worked example
- Walls: 2 × (12 + 12) × 8 = 384 ft² · Ceiling: 12 × 12 = 144 ft² → 528 ft².
- Waste 10%: 528 × 1.10 = 581 ft².
- Sheets: 581 ÷ 32 = 18.2 → 19 sheets of 4 × 8 (or 13 of 4 × 12).
- Finishing: 2 buckets of compound, 1 roll of tape, 2 lb of screws, 2 corner beads.
- 4 × 8 sheet
- 32 ft² · ½″ = 54 lb
- 4 × 12 sheet
- 48 ft² · ½″ = 82 lb
- Joint compound
- ≈ 1 gal per 100 ft²
- Screws
- ≈ 1 lb per 300 ft² (16″ o.c.)
Questions crews ask
How many sheets of drywall for a 12x12 room?
Walls 2 × (12 + 12) × 8 = 384 ft² plus a 144 ft² ceiling is 528 ft²; with 10% waste, 581 ft² → 19 sheets of 4 × 8 or 13 sheets of 4 × 12. Walls only: 14 sheets of 4 × 8.
Should I subtract doors and windows?
Not for a normal room — the cut-outs come back as waste around the openings. Subtract only large openings such as a garage door or a wall of windows.
How much joint compound do I need?
About 1 gallon per 100 ft² of drywall for three coats (tape, fill, skim) — a 4.5 gallon bucket per 450 ft². All-purpose for taping; lightweight or topping for the finish coats. Add a bucket if you are skim-coating.
How many drywall screws per sheet?
About 32 per 4 × 8 sheet at 16″ stud spacing (screws every 12″ in the field, 8″ on edges) — roughly 1 lb of 1¼″ screws per 300 ft². Use 1⅝″ screws for ⅝″ board or over existing drywall.
4x8 or 4x12 sheets?
4 × 12 on walls longer than 8 ft: fewer butt joints, which are the hardest to hide. 4 × 8 for ceilings you are hanging alone, stairwells and tight rooms. ⅝″ Type X is required on garage walls shared with the house and most ceilings at 24″ joist spacing.