Drywall Calculator
Estimate drywall sheets, screws, tape, and total cost for any room.
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How to Use This Drywall Calculator
Enter your room's length, width, and ceiling height in feet. Select the sheet size you plan to use (4×8 is most common), choose whether to include the ceiling, and enter any total square footage for openings like doors and windows. Adjust the waste factor slider to add a buffer for cuts and errors, then hit Calculate.
The tool outputs total sheets needed, total square footage, materials breakdown (screws, joint tape, compound), and an estimated cost — all in one click.
Why This Matters
Buying too little drywall mid-project means emergency hardware store runs and potential dye-lot mismatches. Buying too much wastes money and creates disposal headaches. For a typical 12×14 ft bedroom with 8-foot ceilings, you're looking at roughly 30–35 sheets of 4×8 drywall once you include all four walls and the ceiling — that's $540–$630 just in materials at $18/sheet.
Professional drywall estimators always add a 10–15% waste factor to account for cuts around windows, outlets, and irregular shapes. First-time DIYers often skip this step and end up short. This calculator bakes that buffer in so you get it right the first time. Whether you're drywalling a single bedroom, a basement, or an entire house addition, accurate estimates help you negotiate better prices on bulk material orders and prevent costly delays.
How It's Calculated
Joint tape is estimated at 3 linear feet per sheet. Drywall screws are estimated at 32 screws per sheet (every 8 inches on studs). Joint compound is roughly 0.053 gallons per square foot of finished area.
Tips & Common Mistakes
- Don't skip the waste factor. Even pros use 10–12% for simple rectangular rooms and 15–20% for rooms with angled ceilings or lots of windows.
- Measure openings accurately. A standard exterior door is about 21 sq ft, an interior door is ~18 sq ft, and a typical double-hung window is 12–15 sq ft.
- Choose the right thickness. 1/2" is standard for most walls. Use 5/8" Type X for fire-rated assemblies or garage walls adjacent to living space.
- Account for tall walls. For 9- or 10-foot ceilings, consider 4×10 or 4×12 sheets to minimize horizontal seams and reduce taping work.
- Order all at once. Many suppliers offer per-unit discounts at 50, 100, or 200+ sheet thresholds. It often costs less to round up to the next tier.