How to use this calculator
- Add each wall as a rectangular section.
- Enter optional combined ceiling and opening areas.
- Enter the selected sheet length and width.
- Choose waste and calculate whole sheets.
How the calculation works
Wall areas and optional ceiling area form the gross surface. Openings are deducted, the net area is divided by the entered sheet area, and waste is applied before the final whole-sheet purchase count.
Formula
Gross area = sum(wall length × height) + ceiling area Net area = gross area − openings Purchase sheets = ceil(net area × (1 + waste %) ÷ sheet area)
Worked example
Four 12 ft × 8 ft walls plus a 120 sq ft ceiling total 504 sq ft. Deducting 50 sq ft leaves 454 sq ft. With 4 ft × 8 ft sheets and 10% waste, 499.4 sq ft requires 16 sheets.
Project considerations
- Sheet length and width are visible editable inputs.
- The estimate is area-based and does not optimize seams, cuts, orientation, or offcuts.
- Drywall thickness, type, fire rating, fastening, framing, and code requirements are not recommended.
Frequently asked questions
Is the default sheet size universal?
No. It is an editable example; enter the dimensions of the selected sheet.
Can ceilings be included?
Yes. Enter their combined measured area in the optional ceiling field.