Drywall Calculator

Estimate drywall sheets from room or direct wall area with openings, ceilings, and waste allowance.

Measurement units

Example measurements. Replace the sample values with your own project measurements before calculating.

Describe the drywall area

Use Room mode for four walls and an optional ceiling, or Direct area when you already know the net wall coverage.

Add doors and windows together.

Adds a practical buffer for cuts, settling, or overlap.

Advanced settingsProduct coverage, packaging, and optional pricing

Sheet size and pricing

Choose a standard 4-foot-wide sheet or enter a custom sheet area when the product differs.

Optional. Added once to the estimate.

How this drywall estimate works

Use room mode for a fast wall and ceiling estimate, or direct-area mode when you already know the net surface. The result is a sheet-planning starting point that keeps openings and allowance visible.

How to measure

  1. For room mode, measure length, width, wall height, and the openings you want to subtract.
  2. For direct mode, enter the measured coverage area instead of room dimensions.
  3. Choose whether to add the ceiling, then select the sheet size and allowance that match your plan.

How the estimate works

Calculate gross walls, subtract openings, optionally add the ceiling, apply the allowance, and divide by sheet area.

Worked example

For a 12 × 10 × 8 ft room, start with 352 sq ft of walls. Subtract openings, add a ceiling only when needed, and round the adjusted target to the sheet size you plan to handle.

Before you buy

Plan how sheets will move through doors and stairs before choosing a large format. Include corner bead, screws, tape, compound, and a cut plan separately.

Package and supplier details

Sheet size, fire rating, moisture exposure, offcuts, blocking, soffits, room shape, ceiling coverage, and local requirements can change the order.

Assumptions

  • Room mode models four rectangular walls.
  • Opening areas are subtracted when entered.
  • Whole-sheet rounding happens after the allowance is applied.

Limitations

This does not create a hanging layout or account for fire-rated assemblies, moisture-resistant products, offcuts, blocking, soffits, or local code.

Questions about drywall

Should I include the ceiling?

Include it when the ceiling will use the same sheet material. Leave it out when you are only estimating walls.

Which sheet size should I choose?

Choose a size your plan and site can handle. Doorways, stairs, and the hanging layout matter as much as surface coverage.

Does this include screws and joint compound?

No. The result is for sheet coverage. Plan fasteners, tape, compound, corner bead, and other accessories separately.

Keep the rest of this project estimate moving.

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Related guides

Short, practical help for the next step in this project.

InteriorHow much paint do I need for a room?Measure the room, subtract openings, choose coats, and turn paintable area into whole gallons.Read guide
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