Drywall Calculator
Use room mode for four walls and an optional ceiling, or enter surface areas directly. Sheet orientation and seam layout are not optimized by this estimate.
How to use this calculator
Choose room mode or direct-area mode.
Enter openings and select the sheet dimensions.
Set the allowance and use the rounded-up sheet quantity.
Formula
Net area = wall and ceiling area − openings. Sheets = ceil(net area × (1 + allowance) ÷ sheet area).
Worked example
A net 1,000 ft² area with 10% extra requires 1,100 ft². Using 4 ft × 8 ft sheets gives ceil(1,100 ÷ 32) = 35 sheets.
Assumptions and limits
- Default sheet size is 4 ft × 8 ft.
- Default extra material is 10%.
- Sheet layout, staggered joints, and local code requirements are excluded.
Sources
Related calculators
Frequently asked questions
Should I subtract doors and windows?
Yes for a closer net-area estimate, although installers may retain some opening area as practical cutting allowance.
Can I use metric and US customary units in the Drywall Calculator?
Yes. Unit changes convert the same canonical measurement; they do not reinterpret or round your original value.
When does the calculator round?
The calculation keeps full precision internally and rounds only the displayed result. Whole packages are rounded up at the final step.
Last updated · formula-v1 · content-2026-08-14 · Trusty Calculator Editorial Team