Drywall Calculator
Sheets of drywall, joint compound, tape and screws for a room.
Drywall estimating is really joint estimating. The sheet count is easy arithmetic; what actually determines how long the job takes is how many butt joints you create by hanging short pieces. A room hung in long sheets with staggered seams will tape in half the time of one pieced together from offcuts.
The 10% waste allowance here is the standard for a straightforward room. It is not enough for a room with a vaulted ceiling, multiple soffits or several closets — in those cases, draw the sheet layout before ordering.
How this calculator works
Every field is editable and the result updates as you type — nothing is submitted anywhere, all the maths runs in your browser. That matters for a number you are about to spend money on: you can see exactly which input moved the answer, and by how much.
What this calculation assumes
Assumes 4x8 sheets, 16 inch stud spacing and a level-three finish. Rooms with vaulted ceilings, soffits, bulkheads or many closets need a sheet layout drawn out before ordering, because butt joints cost more time than board.
Treat the result as an order-of-magnitude check rather than a final quantity. Product packaging changes, regional labour rates vary by a factor of two, and no calculator has seen your actual site.
Frequently asked questions
How many screws per sheet of drywall?
Roughly 32 screws for a 4x8 sheet in the field and on edges, at about 1 lb per 250 sq ft of board. Use 1-5/8 inch screws for 1/2 inch board on wood studs, and longer for ceiling work or thicker board.
How much joint compound do I need?
About 4.5 gallons per 1,000 sq ft for a full three-coat finish over taped seams. Buy it in the smallest containers you can work through — opened mud skins over in weeks and cannot be revived.
1/2 inch or 5/8 inch drywall?
1/2 inch for walls in most rooms. 5/8 inch for ceilings, for walls between a garage and living space, and anywhere fire rating or extra sound isolation matters. 5/8 is roughly 30% heavier, which changes how many people you need to hang it.
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