Drywall Calculator
Hanging drywall is the easy half — finishing it takes joint compound, tape, and screws in quantities that surprise first-timers. This calculator totals your wall and ceiling area and converts it into the exact material list: sheets with 10% waste, mud by the gallon, tape by the foot, screws by the box.
Measure the room's perimeter and wall height, and enter the ceiling dimensions (enter 0 if you're skipping the ceiling).
Add up all wall lengths around the room
- Wall area
- 320 sq ft
- Ceiling area
- 100 sq ft
- Total drywall area
- 420 sq ft
- 4×8 sheets (10% waste)
- 15 sheets
- Joint compound
- 7 gallons (approx.)
- Tape
- 240 ft
- Screws
- 480 screws
- Sheet cost (est.)
- $180 – $330
Screws assume 12 in wall / 12 in field ceiling spacing (about 32 per sheet). Mud covers tape coat, two fill coats, and skim — hot mud or a finish level 5 needs more.
How This Calculator Works
Sheets = (Perimeter × Height + Ceiling area) ÷ 32 × 1.10- Wall area = room perimeter × wall height. Add ceiling length × width if you're boarding it.
- A standard 4 ft × 8 ft sheet covers 32 sq ft — divide total area by 32.
- Add 10% for cuts, breakage, and odd-size pieces.
- Joint compound: roughly 1–2 gallons per 100 sq ft for tape plus two coats.
- Tape: ~16 ft of joint per sheet; screws: ~32 per sheet at 12 inch spacing.
Example: A 10 ft × 10 ft room, 8 ft walls, with ceiling: walls 320 sq ft + ceiling 100 sq ft = 420 sq ft ÷ 32 = 13.1 → 15 sheets with waste, ~6 gallons of mud, 240 ft of tape.
Frequently Asked Questions
How much does a sheet of drywall cost in 2026?
A standard 4×8 half-inch sheet runs about $12–$22 depending on region and type — moisture-resistant green board and 5/8 in fire-code board cost more. A 10 ft × 10 ft room with ceiling needs roughly 15 sheets, so $180–$330 in board alone.
Should I hang drywall vertically or horizontally?
Horizontal hanging is the modern standard for walls under 9 ft: fewer butt joints (the hardest to finish), and each sheet spans more studs. Vertical works for commercial fire assemblies or concrete-wall furring. Either way, stagger your joints between rows.
How much joint compound do I need?
Plan 1–2 gallons of all-purpose mud per 100 sq ft of drywall for a standard three-coat tape-and-finish. A 4×8 bedroom typically takes 4–7 gallons including wastage. Buy an extra bucket — running out mid-skim is universal.
What drywall thickness should I use?
½ inch is the standard for walls and flat ceilings; 5/8 inch for ceilings over 24 in joist spacing, garages (fire separation), and sound dampening between layers. Lightweight ½ in board is easier to hang solo but sags more on 24 in ceilings.
How many screws go into a sheet of drywall?
About 32 per 4×8 sheet at 12 inches on center in the field and 8 inches on edges — roughly 1.3 screws per square foot. Over-screwing breaks the paper and creates finish bumps; under-screwing causes nail pops later.
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Last updated: 2026-10-26