About & methodology

Drywall Calculator is a free tool that estimates the full materials bill and installed cost of a drywall job, from the room size or total area. No sign-up; the math runs in your browser.

How it works

• Drywall area = walls (perimeter × ceiling height) + ceiling (length × width) if included, minus ~21 sq ft per door and ~15 per window.
• Sheets = area × 1.10 (10% waste) ÷ sheet size (32 sq ft for 4×8, 40 for 4×10, 48 for 4×12), rounded up.
• Joint compound ≈ 0.5 gallon and tape ≈ 40 linear feet per 4×8 sheet of area, for a standard three-coat finish.
• Screws ≈ 32 per 4×8 sheet of area (≈ 1 per sq ft).
• Cost = sheets + mud + tape + screws (materials) + installation labor ($/sq ft), each as a low–high range.

Default rates

4×8 sheet $12–$18, joint compound $3–$5/gal, tape and screws by the foot/each, installation $1.50–$3.50/sq ft — mid-2020s US ranges for a standard Level 4 finish. These are planning estimates; Level 5 finish, texture, high ceilings, and old-drywall removal cost more. Get quotes for your job.