Calculate exactly how many drywall sheets you need for any room — walls and ceiling. Accounts for doors, windows, sheet size, and waste. Includes cost estimate and mud/tape quantities.
Room dimensions Walls + ceiling
ft
ft
ft
Subtract openings
Each ≈ 21 sq ft
Each ≈ 15 sq ft
Fireplaces, archways, etc.
Sheet & material options
$
1/2 in 4×8 sheet: $12–$20
—
sheets of drywall
Including 12% waste
—
Total sq ft
—
Sheet cost
—
Buckets of mud
Wall area (gross)—
Openings deducted—
Net wall area—
Ceiling area—
Total area to drywall—
Sheet size used—
Sheets (before waste)—
Sheets (with waste)—
Joint tape needed—
Total material cost—
Frequently asked questions
How many sheets of drywall do I need for a 12×12 room? ›
A 12×12 ft room with 9 ft ceilings has about 432 sq ft of wall space. Subtracting a door (21 sq ft) and two windows (30 sq ft) leaves 381 sq ft. Adding the ceiling (144 sq ft) and 12% waste gives about 585 sq ft total — or about 19 sheets of 4×8 drywall. Walls-only without ceiling is about 13 sheets.
What size drywall sheets should I use? ›
4×8 ft (32 sq ft) sheets are the most common and easiest for one person to handle, though heavier than they look at 50–55 lbs each. 4×12 ft sheets mean fewer seams (better finish) but require two people to lift and maneuver. 4×8 is almost always the right choice for DIY; 4×12 is preferred by professionals doing large walls.
How much joint compound (mud) do I need? ›
Plan on about 1 gallon of pre-mixed joint compound per 100 sq ft of drywall for a standard 3-coat finish. Pre-mixed compound comes in 1-gallon and 5-gallon buckets. A 5-gallon bucket covers about 450–500 sq ft. This calculator estimates mud based on your total drywall area. Buy slightly more than calculated — compound is inexpensive and running out mid-job is frustrating.
Should I use 1/2 or 5/8 inch drywall? ›
1/2 inch is standard for interior walls and ceilings in residential construction. Use 5/8 inch (Type X) for garages, utility rooms, or any wall requiring a 1-hour fire rating — most building codes require it between attached garages and living spaces. 5/8 inch is also better for ceilings because it sags less between joists. It weighs about 70–75 lbs per 4×8 sheet vs. 55 lbs for 1/2 inch.
How long does it take to hang drywall? ›
An experienced drywaller can hang about 35–45 sheets per day. A DIYer working carefully will hang 10–20 sheets per day. Plan for 3 separate days of finishing work (taping, first coat, second coat, final coat) with 24-hour drying time between coats. Renting a drywall lift ($40–$60/day) is highly recommended for ceilings — it pays for itself in reduced effort and better results.
About this drywall calculator
This calculator computes the total wall and ceiling area of your room, deducts standard opening sizes for doors, windows, and custom openings, applies your waste factor, and divides by the sheet size to get the exact number of sheets. It also estimates joint compound (mud) and tape quantities so you can buy everything in one trip.
Other materials to buy
In addition to drywall sheets, you'll need: drywall screws (1-5/8 in for walls, 1-1/4 in for metal studs — approximately 1 lb per sheet), joint tape (paper or fiberglass mesh), joint compound (pre-mixed or powder), corner bead for all outside corners, and primer before painting. For ceilings, a drywall lift rental is strongly recommended.