MiniCalci

Calculators & Converters
Construction & DIY

Drywall Calculator

Free drywall calculator for 4x8 and 4x12 sheet counts, joint compound (mud in gallons), drywall screws, and tape. Includes wall and ceiling dimensions with door/window deductions.

~21 sq ft per door

~15 sq ft per window

How many 4×8 sheets, plus mud and screws?

A 4×8 sheet is 32 sq ft. Ceiling and wall area ÷ 32, then round up. Add a waste factor for bad cuts and damaged corners. Joint compound and tape scale with linear feet of seams, which this page estimates from the sheet count — it will not match a commercial takeoff, but it prevents a mid-job run to the store.

US sheet sizes

  • 4×8 is the default. 4×12 reduces seams on 9-ft walls if you can carry it.
  • 1/2-in on walls, 5/8-in Type X often on ceilings or garages (check code).
  • Screws: roughly 1 1/4-in coarse thread into wood studs, about a screw every 12–16 in.

Frequently Asked Questions

How many drywall sheets do I need for a 12x12 room?
For a 12×12 room with 8-foot ceilings including the ceiling: Wall area is 2 × (12 + 12) × 8 = 384 sq ft. Ceiling area is 144 sq ft. Total gross area is 528 sq ft. Subtracting 2 doors and 1 window (~57 sq ft) leaves 471 net sq ft. With a 10% waste factor (518 sq ft), you need **17 sheets of 4×8 drywall** (or **11 sheets of 4×12 drywall**).
Is 4x8 or 4x12 drywall better for DIYers?
4×8 sheets (32 sq ft, ~50 lbs) are much easier to transport in a pickup or SUV and can be lifted and positioned by a single person. 4×12 sheets (48 sq ft, ~75 lbs) create 25% fewer seams and tapered joints for a smoother finish, but require two people or a drywall hoist.
How much drywall mud (joint compound) do I need?
A standard guideline is approximately 0.053 gallons of ready-mixed joint compound per square foot of drywall (covering taping, fill, and skim coats). That equates to about **one 4.5-gallon bucket for every 80–100 square feet of surface area** or roughly 1 bucket per 3 sheets of 4×8.
How many drywall screws per sheet?
Building codes typically require screws spaced every 12 inches on ceilings and every 16 inches on wall studs. That equals approximately **32 to 36 screws per 4×8 sheet** (about 1 to 1.5 lbs of 1-1/4" coarse drywall screws per 5 sheets).

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About these results: Figures are for planning only. Confirm anything you will buy, bill, or submit (materials, payroll, medical screening) against the label, a quote, or a professional.