Drywall Calculator
Estimate drywall sheets required from room dimensions.
Calculation example
Inputs: Room Length: 20 ft, Room Width: 15 ft, Wall Height: 8 ft, Sheet Length: 4 ft, Sheet Width: 8 ft
Result: 18 sheets
A rectangular room with 20 ft length, 15 ft width and 8 ft walls has 560 square feet of wall area before deductions.
Formula
Sheets needed = wall surface area รท sheet area, rounded up.
How to use this calculator
Estimate wall surface area from room dimensions and divide by the area of one sheet, then round up.
Before you calculate
Measure the project dimensions as accurately as practical and keep all measurements in compatible units. For material products, use the coverage, yield, density, or package size stated by the manufacturer or supplier rather than a generic assumption.
Choose the waste allowance based on the project shape, installation method, cutting requirements, and material characteristics. A simple rectangular estimate may need adjustment for openings, corners, slopes, joints, patterns, compaction, or other site conditions.
Understanding the result
The calculator provides a planning estimate based on the inputs shown above. It is not a substitute for project drawings, structural design, manufacturer instructions, or local requirements. Before ordering, compare the calculated quantity with the supplier's package sizes and ordering units.
Tips
- This basic calculator does not subtract doors or windows.
- Ceilings, openings, layout, and local installation practices can change the final quantity.
Frequently asked questions
What does this basic calculator include?
It estimates wall area for a rectangular room and divides by sheet area.
Are doors and windows subtracted?
No. Openings and installation practices can change the quantity.
Related calculators
Use compatible units and verify estimates against project specifications, local requirements and manufacturer instructions.