Measure and MendStart measuring

How many drywall sheets do I need?

Enter rectangular wall or ceiling faces, or use a total you already measured. Then subtract openings and choose the sheet dimensions you plan to buy.

One 12 × 8 ft face minus a 16 sq ft opening is 80 sq ft. With 10% entered waste and 4 × 8 ft sheets, the area calculation requires 3 whole sheets.

Drywall sheet calculator

Measure one or more rectangular faces, or enter a prepared total area. Subtract only measured openings.

3 sheets

80 sq ft net × 1.10 = 88 sq ft; each sheet has a 32 sq ft face.

2.75 exact sheets by area; the purchase count is rounded up only at the final step. Check the actual layout before buying.

View project plan

Calculate once to save this result.

See the formula and scope

(gross surface area − measured openings) × (1 + extra material ÷ 100) ÷ selected sheet face area. This area estimate does not select panel type or thickness and cannot account for seams, cuts, orientation, damage, or a code-required assembly.

Your next step

Use your result to check what comes next before you head to the store.

Area count first, layout check second

The calculator divides adjusted face area by the selected panel face area and rounds the final purchase count up. An area quotient cannot decide sheet orientation, seam placement, cut reuse, edge support, or whether a different layout needs more whole panels.

Use the exact panel you plan to buy

USG lists panel dimensions for the named Sheetrock product, while availability and the required panel type vary by project. Enter the selected width and length; do not treat the initial 4 × 8 ft example as a universal choice.

What this calculator does not select

Panel type, thickness, fire or moisture performance, ceiling suitability, framing, fasteners, joint treatment, structural details, and code-required assemblies are outside this material-area estimate. Confirm those requirements before using the count for purchase.

Sources and notes

Source links reviewed July 16, 2026. A review date is not the document's publication date.

  1. USG: Sheetrock Brand Gypsum PanelsNorth America · manufacturer data sheet

    Panel availability and code-required type vary; verify the chosen panel before purchasing.

  2. National Institute of Standards and Technology: NIST Guide to the SI, Appendix B — Conversion FactorsUnited States · government standard

    Code retains exact defining constants where NIST identifies an exact relationship.