Drywall Calculator

Drywall Calculator

How to Calculate Drywall for Your Project

Drywall (also called sheetrock, wallboard, or gypsum board) is the standard wall covering for modern construction. Whether you're finishing a basement, renovating a room, or building new, accurate drywall calculations save money and reduce waste. Our free sheetrock calculator helps you determine exactly how many sheets you need, plus all the finishing materials like joint compound (mud), tape, screws, and corner bead.

Understanding Drywall and Gypsum Board Measurements

Gypsum wallboard is sold in standard sheet sizes. The most common is 4 feet × 8 feet (32 square feet), but longer sheets reduce seams in rooms with tall ceilings:

4' × 8' (32 sq ft) - Most common, easy to handle
4' × 10' (40 sq ft) - For 9-10 foot ceilings
4' × 12' (48 sq ft) - Fewer seams, requires help to lift

Drywall Thickness Guide

Thickness	Common Uses	Notes
1/4"	Curved walls, repairs, covering old walls	Flexible, requires backing
3/8"	Resurfacing, mobile homes	Lightweight, budget option
1/2"	Standard walls, 16" stud spacing	Most common residential choice
5/8"	Ceilings, fire-rated walls, 24" spacing	Code required for some applications

Types of Drywall

Standard (White) Drywall

Basic gypsum core with paper facing
Used in most living areas
Cost: $12-15 per 4×8 sheet (2025)

Moisture-Resistant (Green Board)

Water-resistant paper and core additives
For bathrooms, laundry rooms, kitchens
Not waterproof—don't use in showers
Cost: $16-18 per sheet

Fire-Resistant (Type X)

Glass fibers in core resist fire spread
Required for garage walls/ceilings attached to living space
5/8" Type X provides 1-hour fire rating
Cost: $15-17 per sheet

Mold-Resistant (Purple Board)

Fiberglass facing resists mold growth
For high-humidity areas, basements
Can be used as tile backer in some applications
Cost: $19-22 per sheet

Soundproof Drywall

Multiple layers with damping compound
For home theaters, bedrooms, offices
Significantly heavier than standard
Cost: $32-40 per sheet

2025 Drywall Cost Guide

Understanding all the costs involved helps you budget accurately for your drywall project.

Material Costs Per Room

Room Size	Sheets Needed	Materials Cost	With Labor
10' × 10' (8' ceiling)	12-14 sheets	$250-350	$600-900
12' × 12' (8' ceiling)	16-18 sheets	$350-450	$800-1,200
15' × 15' (8' ceiling)	22-26 sheets	$500-650	$1,200-1,800
20' × 20' (8' ceiling)	32-38 sheets	$700-900	$1,800-2,600

Finishing Material Costs

Material	Coverage	2025 Price
Joint compound (4.5 gal bucket)	~65 sq ft finished	$16-20
Paper tape (250' roll)	~14 sheets	$5-7
Mesh tape (300' roll)	~16 sheets	$8-12
Drywall screws (1 lb box)	~32 sq ft	$10-14
Corner bead (8' length)	1 corner	$3-5

Labor Costs

Hanging only: $0.75-1.25 per sq ft
Hanging + taping: $1.50-2.00 per sq ft
Full finish (Level 4): $2.00-2.50 per sq ft
Premium finish (Level 5): $2.50-3.50 per sq ft

Drywall Installation Tips

Planning Your Layout

Start with ceilings if drywalling an entire room
Hang walls horizontally for rooms under 9 feet
Stagger joints so seams don't align
Plan cuts around outlets before hanging
Keep seams away from door/window corners where cracks form

Finishing Levels Explained

Level	Description	Best For
Level 0	No finishing	Temporary construction
Level 1	Tape embedded in compound	Hidden areas, above ceilings
Level 2	One coat over tape	Garages, utility rooms
Level 3	Two coats, suitable for texture	Textured walls/ceilings
Level 4	Three coats, light sanding	Most painted walls
Level 5	Skim coat entire surface	Glossy paint, critical lighting

Common Mistakes to Avoid

Not checking studs: Ensure framing is flat before hanging
Overdriving screws: Paper should dimple, not break
Skipping primer: Joint compound absorbs paint differently
Rushing the mud: Each coat must dry 24 hours before next
Ignoring temperature: Don't install below 50°F

Frequently Asked Questions

How many sheets of drywall do I need for a 12x12 room?

For a 12x12 room with 8-foot ceilings: Walls = 384 sq ft (perimeter 48 ft × 8 ft height), minus ~42 sq ft for door/windows ≈ 342 sq ft. Using 4x8 sheets (32 sq ft each): 342 ÷ 32 = 11 sheets for walls. Add ceiling (144 sq ft) = 5 sheets. Total: approximately 16-18 sheets including 10% waste.

How much does drywall cost per sheet in 2025?

In 2025, standard 1/2" drywall costs $12-15 per 4x8 sheet. Moisture-resistant (green board) costs $16-18, fire-resistant (Type X) $15-17, and mold-resistant (purple) $19-22 per sheet. Prices vary by region and retailer. Bulk orders over 50 sheets often qualify for 10-15% discounts.

What thickness drywall should I use?

1/2" drywall is standard for walls with 16" stud spacing. Use 5/8" for ceilings (reduces sagging), garage walls, and fire-rated applications. 1/4" is used for curved walls or covering damaged surfaces. Building codes may require 5/8" Type X for attached garage walls and ceilings.

How much joint compound do I need per sheet?

Plan for approximately 0.07 gallons of joint compound per square foot of drywall, applied in three coats. A 4.5-gallon bucket covers about 65 sq ft of finished wall. For a room with 20 sheets (640 sq ft), you need approximately 2-3 buckets of all-purpose mud.

Should I install drywall horizontally or vertically?

Horizontal installation is preferred for walls 9 feet or shorter—it creates fewer seams and stronger joints where panels meet at studs. Vertical installation works better for walls over 9 feet to avoid horizontal seams that are harder to finish. Ceilings should run perpendicular to joists.

What is the difference between drywall, sheetrock, and gypsum board?

Drywall, sheetrock, and gypsum board are essentially the same product. "Drywall" is the generic term for gypsum panels used in construction. "Sheetrock" is a trademarked brand name owned by USG Corporation (like Kleenex for tissues). "Gypsum board" refers to the gypsum mineral core. All terms describe the same wall-finishing material.

What finish level do I need for my drywall?

Level 4 (three coats of joint compound, light sanding) is standard for most painted walls. Level 5 (skim coat over entire surface) is required for glossy paints, critical lighting, or smooth textures. Level 2-3 is sufficient for textured walls, garages, or utility rooms. The finish level significantly affects labor costs.

How much does professional drywall installation cost?

Professional drywall installation costs $1.50-3.00 per square foot in 2025, depending on finish level and region. Hanging only costs $0.75-1.25/sq ft. Complete installation with Level 4 finish averages $2.00-2.50/sq ft. Premium Level 5 finish adds $0.50-1.00/sq ft. Regional prices vary: West Coast +25%, Northeast +20%, South -10%.

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