Drywall sheets add up fast, and hauling extras back to the store is no fun. This calculator tells you how many sheets you need for your walls and ceiling, subtracts doors and windows, and estimates joint compound and tape.
Room Dimensions
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Openings
Scenario: You're finishing a 20 ft x 11 ft basement room with 8 ft ceilings, 1 door, no windows, and ceiling included. Using 4x8 sheets.
Result: Wall area is 496 sq ft plus 220 sq ft of ceiling for 716 sq ft total. Subtract 1 door (21 sq ft) for 695 sq ft. Each 4x8 sheet covers 32 sq ft, so you need 22 sheets, 3 buckets of joint compound, and 704 screws.
With 8 ft ceilings, a 12x12 room has 384 sq ft of wall. Using 4x8 sheets (32 sq ft each), you need 12 sheets for the walls. Add 5 sheets if you're also drywalling the ceiling (144 sq ft / 32 = 4.5, rounded up).
Use 4x8 for standard 8-foot ceilings -- it covers floor to ceiling with one sheet. Use 4x12 for 9 or 10 ft ceilings or to span long walls horizontally with fewer seams. Fewer seams means less taping and a smoother finish.
About one gallon of pre-mixed joint compound per 100 sq ft of drywall, and one roll of paper tape per 375 sq ft.
Most building codes require it for fire resistance, especially in kitchens and garages. Even where code is silent on it, drywall behind cabinets blocks moisture and pests. Skip it and you might regret it during the next renovation.
Want to learn more before you start your project?
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