How much drywall do I need for a 12x12 room?

A 12x12 room with 8ft ceilings needs about 16 sheets of 4x8 drywall for walls only. Add 6 more for the ceiling.

Should I use 4x8 or 4x12 sheets?

4x12 sheets mean fewer seams and faster installation, but they are heavier and harder to handle. Use 4x12 for long walls, 4x8 for smaller areas.

How many screws per sheet of drywall?

Use about 32 screws per 4x8 sheet (one every 12 inches on edges and 16 inches in the field). That is roughly 1 screw per square foot.

How much joint compound do I need?

Approximately one 4.5-gallon bucket per 50 square feet of drywall. You will need more for textured finishes or if taping many seams.

Drywall Calculator

Calculate drywall sheets, screws, joint compound, and tape needed for walls and ceilings. Choose from 4x8, 4x10, or 4x12 foot sheets with waste factor.

Room & Sheet Specifications

Unit System

Sheet Size

Room Length

Room Width

Ceiling Height

Doors

Windows

Waste (%)

Include ceiling

Insulation Estimation

Estimate Wall Insulation

Target R-Value

Wall Dimension Mode

Estimated Materials

Enter values and click Calculate.

Drywall & Insulation Calculation Formulas

� Wall Area: Perimeter = 2 � (Length + Width). Area = Perimeter � Height.Net Wall Area = Wall Area - (Doors � 21 sq ft) - (Windows � 12 sq ft)

� Total Area & Drywall Sheets: Drywall Area = (Net Wall Area + Ceiling Area) � (1 + Waste Margin).Drywall Sheets = ?Drywall Area � Sheet Size Area?

� Insulation Roll Requirements: Based on selected target R-Value coverage and wall dimensions (Length L � Height H).Insulation Area = L � H (or Net Wall Area for Room)Rolls Needed = ?Insulation Area � Roll Coverage?

� Standard Roll Coverage: R-13 = 40 sq ft/roll | R-19 = 49 sq ft/roll | R-30 = 31.25 sq ft/roll | R-38 = 32 sq ft/roll. Metric conversion: 1 sq ft � 0.0929 m�.

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How to use Drywall Calculator

Select sheet size and enter room dimensions (length, width, ceiling height).
Add the number of doors and windows to subtract their area.
Click Calculate for sheets needed, screws, joint compound, and tape estimates.

What is Drywall Calculator?

A drywall calculator estimates the number of drywall sheets and related supplies needed for a room. It calculates wall and ceiling area, subtracts door and window openings, then divides by sheet size to determine the quantity needed.

This calculator also estimates screws (about 1 per square foot), joint compound, and tape. It supports standard 4x8, 4x10, and 4x12 foot sheets and includes a configurable waste factor.

FAQ

How much drywall do I need for a 12x12 room?: A 12x12 room with 8ft ceilings needs about 16 sheets of 4x8 drywall for walls only. Add 6 more for the ceiling.
Should I use 4x8 or 4x12 sheets?: 4x12 sheets mean fewer seams and faster installation, but they are heavier and harder to handle. Use 4x12 for long walls, 4x8 for smaller areas.
How many screws per sheet of drywall?: Use about 32 screws per 4x8 sheet (one every 12 inches on edges and 16 inches in the field). That is roughly 1 screw per square foot.
How much joint compound do I need?: Approximately one 4.5-gallon bucket per 50 square feet of drywall. You will need more for textured finishes or if taping many seams.

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Author

Omar Hassan"The Number Cruncher"

Engineer & Unit Conversion Specialist

Omar is a mechanical engineer by training and a unit-conversion enthusiast by passion. He has built calibration systems for aerospace and automotive manufacturers and knows firsthand how a single decimal error can cost millions in rework. His mission is to make every conversion instant, accurate, and accessible to everyone, whether they are a student, tradesperson, or practicing engineer, with no advanced degree required.

📖 Drywall Calculator on Wikipedia·Construction Calculators on Wikipedia·Drywall Calculator on Britannica

Last updated: 2026-05-24

Drywall Calculator

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