Drywall Calculator
Calculate sheets, joint compound, and tape needed for drywalling a room
Room Dimensions
Standard 3×7 door = 21 sq ft deducted
Standard 3×4 window = 12 sq ft deducted
Sheet Size
Enter your room dimensions to calculate drywall needed
Tips & Notes
- •Hang sheets horizontally — it reduces the number of butt joints and is easier to tape.
- •Use 5/8" Type X drywall in garages and anywhere fire-rating is required.
- •Moisture-resistant ('green board') drywall for bathrooms; cement board is better for wet areas.
- •Plan 3 coats of joint compound minimum: tape coat, filler coat, finish coat.
- •Sand between each coat with 120-grit, final with 150-grit. Wear a respirator.
Recommended Products
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Tools You'll Need
Pro tips for drywall
- ›Hang sheets horizontally — it reduces the number of butt joints and is easier to tape.
- ›Use 5/8" Type X drywall in garages and anywhere fire-rating is required.
- ›Moisture-resistant ('green board') drywall for bathrooms; cement board is better for wet areas.
- ›Plan 3 coats of joint compound minimum: tape coat, filler coat, finish coat.
- ›Sand between each coat with 120-grit, final with 150-grit. Wear a respirator.
Frequently asked questions
How many sheets of drywall do I need for a 12×12 room?▾
A standard 12×12 room with 8' ceilings has about 480 sq ft of wall surface plus 144 sq ft of ceiling — roughly 624 sq ft total. At 32 sq ft per 4×8 sheet, that's about 20 sheets before subtracting doors and windows. The calculator above does this for you and adds a 10% waste factor.
How much joint compound and tape do I need?▾
Plan on roughly 1 gallon of all-purpose joint compound and 50 linear feet of paper tape per 100 sq ft of drywall. For a typical room you'll go through 2–3 buckets of mud across the tape, fill, and finish coats.
What thickness of drywall should I use?▾
1/2" is standard for walls and ceilings. Use 5/8" Type X in garages, attached firewalls, and ceilings with 24" joist spacing (it resists sag). Use 1/4" for curved surfaces and 1/2" moisture-resistant ('green board') in bathrooms.
How many screws per sheet of drywall?▾
Plan on 32 screws per 4×8 sheet for walls (8" spacing on studs) and 48 per sheet on ceilings (6" spacing). A 1 lb box holds about 200–250 #6 × 1-1/4" screws — enough for 6–7 sheets.
How much does drywall cost in 2026?▾
Materials run $12–$18 per 4×8 sheet plus $10–$15 in mud, tape, and screws per room. Installed, drywall typically costs $1.50–$3.50 per square foot including labor and finishing.