Drywall Calculator

Calculate how many drywall sheets, joint tape, compound, and screws you need for your project.

Wall Area (net) is Wall Length times Wall Height times Number of Walls, minus a standard 21 sq ft for every door and 15 sq ft for every window — so Doors and Windows always subtract from the total rather than being a separate line item. Because door and window openings are usually a small fraction of total wall area, nudging Doors or Windows by one unit barely moves the net area or the sheet count in a small room, but the effect is real and adds up: swapping a 1-door, 2-window room for the same room with 0 doors and 0 windows recovers 51 sq ft, enough to change the sheet count outright in a tight layout. Sheets Needed adds a flat 10% waste factor on top of Net Area divided by Sheet Size and rounds up, since drywall doesn't come in fractional sheets. Wall Length, Wall Height, and Number of Walls all scale Sheets Needed the same way, since they're multiplied together with no other factor between them. Joint Tape Rolls, Joint Compound Buckets, and Screw Boxes are each independent coverage-rate divisions off Net Area — 375 sq ft per tape roll, 480 sq ft per compound bucket, and roughly 1.5 screws per sq ft at 200 screws per box — so all three track Net Area directly rather than Sheets Needed. This estimate assumes standard 1/2-inch drywall on a typical stud layout and does not account for ceiling area, corner bead, or cutouts for outlets and switches.