How this calculator works
Estimate wall and ceiling area, subtract openings where relevant, and divide by sheet coverage. The result is an estimate and may vary with the product, site conditions, measurement accuracy and installation method.
Before you use the estimate
- Measure the area carefully and keep units consistent.
- Review any waste allowance and material coverage assumptions.
- Check the product packaging or supplier specifications before purchasing.
Worked example
500 ft² of wall, 10% waste, 4×8 ft sheets: 500 × 1.1 = 550 ft² → ÷ 32 = 17.19 → 18 sheets. Try these numbers in the calculator above to see each step.
Frequently asked questions
How many drywall sheets do I need for a room?
Enter each wall’s length and height above, subtract door and window openings, and the calculator divides by 32 sq ft (one 4×8 sheet) with waste added.
What size are drywall sheets?
Standard sheets are 4×8 ft (32 sq ft). 4×12 ft sheets are also common and mean fewer seams on long walls.
How much waste should I add for drywall?
10% is typical; use 15% for rooms with many corners, angles or ceiling work. Waste allowance guide →
Planning note: This tool provides general information, not engineering or construction advice. Verify important measurements with a qualified professional when needed.