BuildCalc

Drywall Calculator

Enter the total wall and ceiling area you're covering (or estimate it from room size). The calculator returns sheet count for 4×8 or 4×12 panels with a 10% waste factor, plus screws and joint compound.

Your measurements

ft²
%

Coverage

Area
400 ft²
Sheet area
32 ft²

Materials

Screws
448 screws
Joint compound
1.8 gal

Drywall sheets

14 sheets

Estimates only. Order a little extra for waste and verify against your supplier's coverage figures.

The formula

Sheets = Total area ÷ sheet area × (1 + waste %)

Example: A 12 ft × 12 ft room with 8 ft walls has ~384 ft² of wall — about 14 × 4×8 sheets (incl. 10% waste).

How it works

  1. 1Add up all wall and ceiling area you're covering.
  2. 2Divide by the sheet area: 32 ft² for 4×8, 48 ft² for 4×12.
  3. 3Add ~10% for waste and cuts, then round up to whole sheets.

Frequently asked questions

Should I use 4×8 or 4×12 drywall sheets?

4×12 sheets cover more area with fewer seams (less taping) but are heavier and harder to handle. Use 4×8 for tight spaces or solo hanging.