Drywall Calculator

Estimate drywall sheets, joint compound, tape, screws, waste allowance, and material cost for a room's walls and ceiling.

Room Dimensions

Enter the combined square footage of doors, windows, and other areas that will not receive drywall.

Drywall Sheet

Optional Material Prices

Estimated Materials

Wall Area
Ceiling Area
Net Drywall Area
Drywall Sheets
Joint Compound
Joint Tape
Drywall Screws
Estimated Material Cost

Finishing-material estimates are general planning allowances. Actual use depends on sheet layout, framing spacing, number of seams, corners, finish level, product coverage, and installer technique.

How the Drywall Calculator Works

The calculator finds the surface area of the four walls and optionally adds the ceiling. It subtracts entered openings, adds the selected waste allowance, and divides by the coverage of the chosen sheet size.

Sheets Needed = Net Area × Waste Allowance ÷ Sheet Coverage

How Much Extra Drywall Should You Buy?

A 10% allowance is a useful starting point for ordinary rooms. Complex layouts, angled walls, numerous openings, damaged sheets, or inexperienced cutting may require additional material.

Choosing a Sheet Size

Larger sheets can reduce seams and finishing work but are heavier and more difficult to transport and install. Confirm that sheets can pass through doors, stairways, and other access points before purchasing.

Moisture and Fire Requirements

Bathrooms, garages, utility areas, and rated wall assemblies may require specific drywall products, thicknesses, fasteners, or installation methods. Confirm applicable building requirements before buying.