Drywall Calculator — ft, sheets, tape & cost
How to use this calculator
Enter room dimensions in feet and inches (⅛″ fractions) and the calculator returns the sheet count, joint tape, mud buckets, screws and corner bead you need to take to the supply house. Deduct doors and windows so you do not over-order — a typical 12×14 bedroom with one door and one window draws about 12 sheets of ½″ 4×8 at 10% waste. The plan and elevation diagram redraws as you type; tap any dimension to jump to that input.
Tape & Mud — joint tape rolls (500 ft/roll), joint compound (covers ~100 ft² per coat), 2-3 coats.
Screws — approximately 1 screw per ft², ~1 lb per 100 screws.
Cost — price per sheet, per tape roll, per mud bucket, per lb of screws.
Saved Calculations
| Time | Mode | Area ft² | Sheets | Tape | Mud | Screws | Total $ |
|---|
How to Calculate Drywall for a Room
Sheet counts here follow gypsum board manufacturer coverage data (ASTM C1396 board, USG/CertainTeed/National Gypsum field tables). Quantities are net-area driven and rounded up to whole units because partial sheets, rolls and buckets are not sold. Build a 5% allowance for a clean rectangular room, 10% for an average job, and 15–20% where there are many corners, soffits, returns or odd-angle cuts. Once the board is up, run the paint calculator on the same wall area to size primer and finish coats.
Formulas Used
Net area = gross wall or ceiling area − door openings − window openings.
Sheets = ceil(net area × (1 + waste%) ÷ sheet area), with sheet area 32, 40 or 48 ft².
Joint tape = total board joints (≈ sheets × (sheet length + 4 ft) ÷ 2) ÷ 500 ft per roll.
Joint compound = net area ÷ 100 ft² per coat × coats (2 for a standard Level 4, 3 for Level 5).
Screws ≈ 1 per ft² (~32 per 4×8 sheet, 1¼" coarse-thread, ~1 lb per 100).
Frequently Asked Questions
What size drywall should I use? 4×8 is standard and easiest to handle solo; 4×12 sheets cut joint footage roughly in half but are heavy and need two installers. Use ½" for most walls and ceilings and ⅝" Type X for fire-rated assemblies or sound control.
How much waste should I plan for? 10% suits typical rectangular rooms. Use 15–20% for cut-heavy layouts, and plan sheet orientation before cutting to keep offcuts usable.
What else do I need to finish? Pair this with the tile & grout calculator for wet areas, the flooring and carpet calculators for the floor, or the block wall calculator when the partition is masonry rather than studs.
On install day
Three things estimators forget. Hang ceilings first — walls support the ceiling sheet edges, so order ceiling board separately if you are running ⅝″ up there. Corner bead and inside corners — a 12×14 room hides roughly 32 lf of inside corners and 10–16 lf of outside corners that the gross-area math misses; add them to the corner-bead input or you will be one short. Mud yield — a 5 gal pre-mix bucket covers ~100 ft² per coat at Level 4, so a 400 ft² room needs about 8 buckets across two coats. 2025 USA pricing runs $12–16 per ½″ 4×8 sheet, $4–6 per 500 ft roll of paper tape, $15–20 per 5 gal bucket of all-purpose mud, and $80–120 per hanger-day. IRC R702.3.5 sets minimum fastener spacing — 7″ on ceilings, 8″ on walls for screws.
