Drywall Calculator

Enter your room size. Get the sheets, mud, tape and screws.

100% in your browser - no upload, no sign-up.

How to use this drywall calculator

1. Enter your room length, width and ceiling height in feet.
2. Tick the ceiling if you're drywalling it, and choose your sheet size.
3. Read the sheets, joint compound, tape and screws - a 10% waste allowance is included.

How the drywall estimate is calculated

Wall area is the room's perimeter times the ceiling height - 2 × (length + width) × height - and the ceiling adds length × width when included. That area is divided by the coverage of one sheet: a 4×8 sheet is 32 ft², a 4×10 is 40 ft², and a 4×12 is 48 ft². From the sheet count come the fasteners and finishing: about 32 screws per sheet, roughly 3 gallons of joint compound per 100 ft², and about 1 linear foot of tape per square foot. A 10% waste allowance is added by default for cuts and offcuts.

Frequently asked questions

How many sheets of drywall do I need?

Divide your total wall (and ceiling) area by the coverage of one sheet - 32 ft² for a 4×8, 48 ft² for a 4×12 - then add about 10% for cuts. A 12 × 12 ft room with 8 ft walls is roughly 384 ft² of wall, or about 13 sheets of 4×8 board. Enter your room above for an exact count.

How much joint compound and tape do I need?

Plan on about 3 gallons of joint compound per 100 square feet of drywall for a standard three-coat finish, and roughly 1 linear foot of tape for every square foot. A 5-gallon bucket of all-purpose mud covers around 165 ft². This calculator totals both from your room size.

Should I use 4×8 or 4×12 sheets?

Longer 4×12 sheets cover more per board and leave fewer butt joints to tape and finish, which gives a flatter wall - but they're heavy and awkward to handle solo. 4×8 sheets are easier for one person and tight spaces. Pick the size you can safely carry; the calculator adjusts the sheet count either way.