Drywall Calculator

Standard 4×8 ft sheets cover 32 sq ft each. Assumes 8 ft ceilings, walls + ceiling, 10% waste factor. Add 1 box of screws per 8 sheets, 1 gallon mud per 4 sheets, 250 ft tape per 8 sheets.

Use 5/8 inch sheets on ceilings 24+ inches OC and on garage ceilings (fire code). Moisture-resistant green-board for bathrooms (around tubs/showers only). Cement board behind tile.

The complete drywall materials list: sheets, screws, joint compound (mud), and tape. People skip the latter three and then make 4 store trips during a single weekend project. Our calculator does the full list with realistic quantities.

Formula: wallArea = perimeter × height, minus doors and windows, sheets = ⌈(wallArea + ceiling) × 1.15 ÷ sheetArea⌉. The 15% covers waste from cuts and odd corners.

Sheets

Standard 4×8 sheet covers 32 sq ft. 4×12 covers 48 sq ft. 4×12 is great for tall walls because it eliminates a horizontal seam, but it needs 2 people to install (one sheet weighs 80 lbs).

Screws

About 32 screws per sheet for walls, 36 for ceilings. Buy 1 lb per 4 sheets - about 350 screws per pound for 1-5/8 inch drywall screws.

Joint compound (mud)

A 5-gallon bucket (60 lb) of premixed mud covers about 1,000 sq ft of finished area through all coats. Always buy at least one extra bucket - running out mid-coat is brutal.

Tape

About 1 linear foot of tape per sq ft of drywall as a rough rule. Standard paper tape rolls are 250 feet.

4×8 sheets (32 sq ft): Easier to move, carry, and install solo. Best for most rooms.

4×12 sheets (48 sq ft): Fewer horizontal seams on tall walls. Best for ceilings of 9+ ft rooms. Needs two people minimum.

• Regular (white) - for most walls and ceilings. Cheapest. 1/2 inch thickness is standard.
• Moisture-resistant (green board) - for bathrooms within 18 inches of water sources.
• Cement board (Durock) - under tile in showers and tub surrounds. Required, not optional.
• Type X (fire-rated) - for walls between garage and house, around furnaces. 5/8 inch thickness.
• 5/8 inch ceiling sheets - for ceilings to prevent sag between joists 24 inches apart.
• Soundproof drywall (QuietRock) - bedroom walls in townhouses, home theaters. Pricey but effective.

• Three coats minimum: tape coat (fills seam + holds tape), second coat (4-6 in wide, fills tape edges), skim coat (10-12 in wide, feathers everything smooth).
• Sand between every coat with 220 grit. Wear a mask and use a damp shop vac to control dust.
• Use mesh tape for corners that flex. Paper tape for flat seams (stronger).
• Joint compound shrinks as it dries - multiple thin coats beat one thick coat every time.
• Allow 24 hours between coats for premixed mud, 1-2 hours for setting type (90, 45, 20 numbers refer to working time in minutes).
• Prime before paint. Drywall absorbs paint differently than joint compound - primer evens it out.

Rough estimating rule for joint compound: about 1 gallon of all-purpose mud per 100 to 200 sq ft of drywall, depending on how many coats and how much texture you add. Tape runs about 400 ft per 1,000 sq ft of drywall. A standard bucket holds 4.5 gallons. Treat these as approximate starting figures and buy a little extra so you never run out mid-coat.

Light 3-coat finishes land near the 200 sq ft per gallon end. Skim coating the full surface or adding a heavy texture pushes you toward 100 sq ft per gallon, so plan on roughly double the compound for those jobs. One 250 ft roll of paper tape covers a single average room with margin to spare.

The common estimate: a standard 4.5 gallon bucket of all-purpose joint compound covers roughly 475-500 sq ft of drywall through a basic tape coat plus two finish coats. Since a 4×8 sheet is 32 sq ft, that works out to about one bucket per 8 to 12 sheets of board once you account for heavier coats, corners, and texture.

Worked example for a light 3-coat finish: 500 sq ft per bucket ÷ 32 sq ft per 4×8 sheet ≈ 15 sheets. On a job where you skim coat the whole surface or add texture, coverage drops to about 8 to 12 sheets per bucket. Per single sheet that is roughly 0.4 to 0.6 gallon of mud, so a 12 sheet room needs about 4 to 5 gallons, or one bucket.

To calculate drywall mud for any job, take your total drywall square footage and divide by a coverage figure between 100 and 200 sq ft per gallon: gallons = drywall sq ft ÷ 150 is a safe middle estimate. Multiply gallons by roughly 0.22 to convert to 4.5 gallon buckets.

Screws per sheet

Plan on about 32 screws per sheet on walls and 36 per sheet on ceilings, following framing at 16 inches on center. That is roughly 1 lb of 1-5/8 inch screws for every 4 sheets, since a pound holds about 350 screws.

Tape length

The quick rule of about 1 linear foot of tape per sq ft of drywall is a generous upper bound that guarantees you never run short. A tighter estimate based on actual seam length is closer to 400 ft per 1,000 sq ft of drywall. Standard paper tape rolls are 250 ft, so a single average room usually needs one roll or less.

Number of coats

A proper finish is three coats of mud minimum: the tape coat that beds the tape into the seam, a fill coat that widens and levels it, and a skim coat that feathers everything smooth. More coats and wider feathering use more compound, which is why the same wall can land anywhere from 100 to 200 sq ft of coverage per gallon.

How many buckets of mud per sheet of drywall?

About one 4.5 gallon bucket of joint compound per 8 to 12 sheets of 4×8 drywall for a typical tape and finish job, or up to roughly 15 sheets per bucket for a light 3-coat finish. Per single sheet that is about 0.4 to 0.6 gallon of mud.

How much drywall mud do I need?

Estimate 1 gallon of all-purpose compound per 100 to 200 sq ft of drywall. For 1,000 sq ft of board that is about 5 to 10 gallons, or roughly 1 to 2 standard buckets. Round up and keep one spare bucket on hand for texture and touch-ups.

How many boxes of mud per sheet of drywall?

Pre-mixed all-purpose compound sold in a box holds about the same 4.5 gallons as a bucket, so plan the same 8 to 12 sheets per box. Setting-type compound sold as powder (typically an 18 lb box) mixes to roughly 2 gallons of usable mud, enough for about 4 to 6 sheets on the tape and fill coats.

How much drywall tape per room?

A single 12×12 room has around 464 sq ft of drywall, which needs roughly 200 ft of tape at the 400 ft per 1,000 sq ft rate. That fits inside one 250 ft roll with margin. Larger open rooms with more seams push toward the full roll.