Drywall calculator for sheets, mud, tape and screws

About one 4.5 gal pail of ready-mix all purpose compound for every 450 sq ft of drywall, or roughly 14 sheets of 4 × 8. That comes from a manufacturer's published coverage of about 10 gal per 1,000 sq ft for three coats. Fifty sheets of 4 × 8 is 1,600 sq ft, so about 16 gal, or 4 pails. Answers on trade forums run from one bucket per 10 sheets to half that, because experience changes how much mud a finisher uses. A first-timer should round up and keep the extra pail sealed so it can go back.

Subtract them if you also add a 10% to 15% waste allowance; skip them if you want the cut-outs to be your waste. Some professional hangers on trade forums subtract nothing for normal windows and doors, since the piece cut from the opening is scrap and offcuts rarely fill another spot. Do subtract large openings such as a patio door, a cased opening or a garage door. The calculator subtracts 21 sq ft per door and 15 sq ft per window; set both to 0 to estimate the trade way.

About 28 to 35 screws for a 4 × 8 sheet, roughly one per square foot. At the IRC maximum spacing, a 4 × 8 sheet on a wall with studs 16 in apart takes 28 screws (screws every 16 in on seven studs), and the same sheet on a ceiling with joists 16 in apart takes 35 (screws every 12 in). A 4 × 12 wall sheet takes about 40. Many hangers add one or two per stud. For a whole job, the calculator multiplies the net square footage by one and rounds to the next 50.

Use 4 × 12 when you can handle it, because longer sheets mean fewer butt joints, and butt joints are the hardest seams to finish flat. A 12 ft wall takes one 4 × 12 per row with no seam, against a sheet and a half of 4 × 8. Use 4 × 8 when you work alone, carry sheets up stairs or through tight doors, or cover small rooms and closets. The sheet count for the same room is close either way: the 12 × 10 ft example room takes 15 sheets of 4 × 8 or 10 of 4 × 12.

Two rows of 54 in board, hung horizontally, cover a 9 ft wall with no strip, and 54 in sheets usually come 12 ft long. With standard 48 in board you hang two rows and fill a 12 in strip, which adds a joint that installers on trade forums say tends to shrink, so they bed it with setting-type compound. Another option is 4 × 9 ft or 4 × 10 ft sheets hung vertically. Ask your supplier first: posters on the same forums report that 54 in board is a special order in some areas.

Yes, if the sheets run perpendicular to the joists: IRC Table R702.3.5 allows 1/2 in board on a ceiling at 24 in on center only in that orientation, with screws every 12 in. If a water-based texture will be sprayed on, note d of the same table raises it to 5/8 in, or 1/2 in sag-resistant ceiling board. Garage ceilings with rooms above need 5/8 in Type X. Hangers on forums report sagging when 1/2 in board goes on 24 in framing, which is why 5/8 in is the common choice.

17 sheets of 4 × 8 for walls and ceiling with 8 ft walls, one door, one window and 10% waste. The walls are 48 ft of perimeter × 8 ft = 384 sq ft and the ceiling 144 sq ft, so 528 sq ft gross and 492 sq ft after the door and window. With 10% that is 541.2 sq ft ÷ 32 = 16.91, rounded up to 17. Without subtracting the openings it is 19. In 4 × 12 board the same room takes 12 sheets. Finishing it takes about 4.9 gal of compound and 172 ft of tape.

Roughly 121 sheets of 4 × 12, or 181 of 4 × 8, for a single-story 1500 sq ft house with 8 ft walls. Drywall hangers on trade forums estimate a whole house at about 3.5 times the floor area for 8 ft walls, and about 3.9 times for taller walls and vaulted ceilings. For 1,500 sq ft that is about 5,250 sq ft of board; with 10% waste, 121 sheets of 4 × 12. Treat it as a rough check only. A room-by-room count with the calculator is what you should order from, since closets, stairwells and garages change the total.

About 350 ft of joint tape per 1,000 sq ft of drywall, from a gypsum manufacturer's estimating table; estimators on trade forums use 370 to 400 ft. Per sheet that is about 11 ft for a 4 × 8 and 17 ft for a 4 × 12. A 500 ft roll covers roughly 1,400 sq ft of board, so one roll does a typical bedroom with ceiling and a 250 ft roll does a small bath. Inside corners take tape too; outside corners take corner bead instead. Paper tape is the usual choice for ceilings and corners; mesh tape is common with setting-type compound.

Three coats over the tape, fastener heads and corner bead, which is the minimum one manufacturer's all purpose compound data sheet calls for: a taping coat that beds the tape, a fill coat, and a finish coat feathered about 2 in wider each time. Fastener heads get their own spot coats. A smooth wall under non-flat paint may need a Level 5 finish, which adds a thin skim coat over the entire surface and noticeably more compound. The calculator's 10 gal per 1,000 sq ft figure covers the three-coat finish; raise it if you plan a skim coat.

It depends on thickness and product. One manufacturer's lightweight 1/2 in board weighs 1.2 to 1.4 lb per sq ft, so a 4 × 8 sheet is about 38 to 45 lb and a 4 × 12 about 58 to 67 lb. Its lightweight 5/8 in Type X board weighs 1.9 lb per sq ft, about 61 lb for a 4 × 8 and 91 lb for a 4 × 12. Standard-weight board is heavier than these lightweight figures. Weight is why many people working alone choose 4 × 8 sheets and rent a panel lift for ceilings.

At least 1/2 in gypsum board on the garage side of the wall between the garage and the house and attic, and 5/8 in Type X on the garage ceiling when there are habitable rooms above. That is IRC Table R302.6 in the 2021 model code. The Type X garage ceiling also has tighter fastening in Table R702.3.5: framing at 24 in on center maximum and nails or screws every 6 in. Installers on garage forums describe hanging 5/8 in Type X on the walls as well as the ceiling. Check your local adoption, because jurisdictions amend the garage separation rules.

Add 10% for an ordinary room and 15% for rooms with many corners, soffits, angled ceilings or small closets. These are trade rules of thumb; no code or gypsum standard sets a waste figure. Apply the allowance once, to the net square footage or to the sheet count, not both, and do not add it on top of rounding each wall up to a full sheet. If you leave doors and windows in the measurement, use little or no waste. The calculator applies waste to the sheet count only and warns below 10%.

Measure it: add up the height of every outside corner and the edges of each window, soffit or opening you wrap with drywall, then divide by the stick length and round up. A room with two 8 ft outside corners and one 3 × 5 ft window wrapped on both sides and the top needs 16 + 5 + 5 + 3 = 29 ft, which is four 8 ft sticks. Contractors on trade forums note that corner bead varies from a few sticks to hundreds per house, so no per-sheet ratio works. Enter the length in the calculator's outside corner field.

1/2 in for walls and 1/2 in or 5/8 in for ceilings, depending on joist spacing and texture, under IRC Table R702.3.5. Thickness by room, Type X and moisture-resistant board are covered in drywall sizes, thickness and screws.