Free interior calculator

Drywall Calculator

Estimate whole drywall sheets from measured surface area. Subtract doors and windows, choose a verified common sheet size or enter a custom size, and keep the waste allowance visible.

Calculate drywall sheets

How sheet count is calculated

The calculator determines gross surface area, subtracts entered openings, applies your extra/waste allowance, then divides by the selected sheet coverage and rounds up to a whole sheet.

sheets = ceiling(net area × (1 + waste %) ÷ sheet area)

Drywall and Sheetrock calculations

People sometimes search for a “Sheetrock calculator” when they need a drywall sheet count. Sheetrock is a USG brand name; the quantity method is still based on measured surface area, the dimensions of the board you plan to buy and the waste allowance you choose.

Common launch sheet-size presets

The 4 × 8, 4 × 10 and 4 × 12 ft presets are based on USG Sheetrock installation documentation. Custom dimensions remain available for other products.

See our source policy.

What this calculator does not decide

Sheet quantity is not the same as wall-system design. Board type, thickness, fire rating, moisture resistance, framing, fastening and local code must be determined from your project requirements.

Before ordering drywall

Confirm the board type, thickness and actual sheet dimensions required by the project before using the purchase count. Large openings can be subtracted, but small cutoffs are not automatically reusable across every wall. Keep the waste input tied to the layout and cutting plan you actually expect.

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