Drywall Calculator
Use this free drywall calculator to estimate materials for hanging and finishing drywall. Enter your room dimensions, subtract doors and windows, and optionally include the ceiling for a complete material list.
How to Use This Calculator
- 1
Measure the room
Enter room length, width, and wall height in feet.
- 2
Count openings
Enter the number of doors and windows to subtract.
- 3
Select sheet size
Choose 4x8 (standard) or 4x12 (fewer seams) sheets.
- 4
Review your materials
See sheet count, joint compound, tape, screws, and estimated costs.
Frequently Asked Questions
Calculate the total wall and ceiling area in square feet, then divide by the sheet size (32 sq ft for 4x8, 48 sq ft for 4x12). Add 10% for waste from cuts. Our calculator does this automatically and subtracts door and window openings.
4x8 sheets are standard and easiest to handle. 4x12 sheets are better for rooms with 9 or 10-foot ceilings because they cover more wall area with fewer seams, resulting in less taping and a smoother finish.
Plan for about 1 gallon of pre-mixed joint compound per 19 square feet of drywall (roughly 1.5 gallons per 4x8 sheet). You will apply 2–3 coats: taping, fill, and finish. Buy a little extra for touch-ups.
Hanging drywall is manageable for DIYers, though ceilings and heavy 4x12 sheets are challenging alone. Taping and finishing (mudding) requires more skill for smooth results. Renting a drywall lift makes ceiling installation much easier.