Drywall Calculator

How many sheets of drywall do you need? Calculate sheets, joint compound, tape, screws, and cost for walls & ceilings.

Wall Dimensions
Wall / Section 1
ft
ft
Ceiling (Optional)
ft
ft
Openings & Options
Quick Reference: Drywall Sizes
Sheet SizeCoverageBest ForApprox. Cost
4' × 8'32 sq ftStandard rooms, 8ft ceilings$10-15
4' × 10'40 sq ftRooms with 9-10ft ceilings$13-18
4' × 12'48 sq ftTall ceilings, fewer joints$15-22
4' × 14'56 sq ftCommercial, very tall walls$18-26

How Drywall Calculation Works

1
Measure Walls

Measure length × height of each wall section. Add multiple walls for L-shaped or multi-section rooms.

2
Deduct Openings

Subtract doors (21 sq ft each) and windows (12 sq ft each) from the total wall area.

3
Add Waste

Add 10-20% for cuts, corners, and installation errors. Standard is 10% for rectangular rooms.

4
Get Materials

Divide by sheet area to get sheets needed, plus joint compound, tape, screws, and corner beads.

Frequently Asked Questions

For a standard 12×12 room with 8ft ceilings: 4 walls × 12ft × 8ft = 384 sq ft of walls. Add 144 sq ft ceiling = 528 sq ft total. Subtract 2 doors (42 sq ft) and 1 window (12 sq ft) = 474 sq ft net. With 10% waste = 521 sq ft ÷ 32 sq ft per 4×8 sheet = 17 sheets.

4×8 is standard and easiest to handle (one person can carry it). Use 4×12 for taller ceilings or to eliminate horizontal seams. Longer sheets mean fewer joints to tape and finish, saving time on finishing work.

1/2" is standard for walls. 5/8" is required for ceilings (resists sagging between joists) and fire-rated applications (garage walls adjacent to living spaces). 1/4" is for curved walls or covering damaged plaster. 3/8" is for layering over existing drywall.

Materials for a 12×12 room cost $200-$400 (17 sheets + joint compound + tape + screws). Professional installation adds $1.50-$3.00 per sq ft ($750-$1,500 for the same room). Total DIY cost is typically 40-60% less than hiring a contractor.

Complete Guide to Drywall Installation in 2026

DIY Drywall Tips

Hang ceiling sheets first, then walls. Start from corners and work outward. Use a T-square for straight cuts and a utility knife for scoring. Pre-drill screw locations for easier fastening. Leave a 1/4" gap at the floor for expansion. Stagger joints between rows for structural strength.

Fire-Rated Drywall

Type X (5/8") drywall is required between garages and living spaces per building code. It provides 1-hour fire resistance. Type C offers even more protection. Always check local building codes for your specific requirements before starting a project.

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