Drywall Calculator
Find out how many sheets of drywall and how much joint compound you need for your project.
- Drywall sheets (4×8)28 sheets
- Joint compound43 gallons
- Drywall tape800 lin ft
- Total area incl. waste880 sq ft
How to use
- Enter the total wall area in square feet (length × height for each wall, added together).
- Enter the ceiling area if you are drywalling the ceiling too.
- Set a waste allowance (10% is typical) and read the sheet count.
About this calculator
This drywall calculator divides your total area by the coverage of one standard 4×8 sheet (32 sq ft). It adds a waste allowance for cuts around outlets, windows and doors. Joint compound is estimated at roughly 0.053 gallons per square foot for three-coat work (that's about 1 gallon per 19 sq ft). Drywall tape is estimated at 1 linear foot per square foot of drywall. Always round up to whole sheets and buckets.
🧮 How it's calculated
- 1Step 1 — Total area: Total = Wall area + Ceiling area
- 2Step 2 — Add waste: Area with waste = Total × (1 + Waste% ÷ 100)
- 3Step 3 — Sheets: Sheets = ⌈Area with waste ÷ 32⌉ (one 4×8 sheet = 32 ft²)
- 4Step 4 — Joint compound: Gallons = ⌈Total area × 0.053⌉
- 5Step 5 — Drywall tape: Tape (ft) = Total area × 1
Sheets = ceil( Total area × (1 + Waste%) / 32 ); Joint compound (gal) = Total area × 0.053.
Frequently asked questions
What size is a standard sheet of drywall?+
4 feet wide by 8 feet tall is the most common size, covering 32 square feet. 4×12 sheets are also available and reduce seams.
How thick should drywall be?+
1/2 inch is standard for walls and ceilings. Use 5/8 inch for fire-rated assemblies or ceilings with widely spaced joists.
How much joint compound do I need?+
A rough guide is one 4.5-gallon bucket per 100 square feet of drywall for a three-coat finish. This calculator estimates that automatically.