Drywall Calculator — Sheets, Joint Compound & Tape

    Calculate how many drywall sheets you need plus joint compound, tape, screws, and corner bead. Works for full rooms, individual walls, ceilings, or custom square footage. Includes 10% waste factor.

    $/ sheet

    Tips

    • Thickness — use 1/2" for walls and 5/8" for ceilings or fire-rated assemblies.
    • Hanging order — hang ceilings first, then walls. Top sheets before bottom.
    • Mud coats — plan for 3 coats: tape coat, fill coat, finish coat. Sand between coats.
    • Moisture areas — use moisture-resistant (green board) in bathrooms and kitchens.
    • Screw spacing — every 8" along edges, 12" in the field for walls; 7" for ceilings.

    Example Calculation

    Drywalling a 12×14 foot room with 8-foot ceilings, 2 doors, 2 windows, and including the ceiling? Total area is approximately 512 square feet. Using 4×8 sheets, you need about 18 sheets of drywall, 2 buckets of joint compound, 2 rolls of tape, 6 boxes of screws, and 4 pieces of corner bead. At $12–$16 per sheet, the drywall alone costs $216–$288.

    Drywall Sheets by Room Size

    Room SizeWalls OnlyWalls + Ceiling
    10×10, 8 ft ceiling912
    10×12, 8 ft ceiling1014
    12×14, 8 ft ceiling1218
    14×16, 8 ft ceiling1522
    16×20, 8 ft ceiling1829

    All estimates include 10% waste and subtract 2 doors and 2 windows.

    Frequently Asked Questions

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

    For walls only with 8-foot ceilings (minus 2 doors and 2 windows), approximately 11 sheets of 4×8 drywall. Add 5 more sheets if you are also doing the ceiling.

    What thickness of drywall should I use?

    1/2 inch is standard for walls. Use 5/8 inch for ceilings (it resists sagging) and for fire-rated walls (garages, furnace rooms). Use 1/4 inch for curved surfaces.

    How much joint compound do I need?

    Approximately one 4.5-gallon bucket per 100 square feet of drywall when applying the standard three coats (fill, cover, finish).

    Should I hang drywall horizontally or vertically?

    Horizontally for walls. This creates fewer seams on 8-foot walls and places the tapered edges together for easier finishing. Hang ceilings first, then walls.

    How many screws per sheet of drywall?

    Approximately 32 screws per 4×8 sheet when studs are 16 inches on center. Place screws every 8 inches along edges and every 12 inches in the field.

    Typical Results

    Bedroom(12' × 12', 8' ceiling)14–16 sheets
    Basement finish(~800 sq ft walls + ceiling)35–45 sheets
    Whole house(2,000 sq ft home)150–200 sheets

    💡 Use 4×12 sheets for rooms wider than 8' — fewer seams to tape.