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Drywall Calculator

Find how many drywall sheets a room's walls (and ceiling) need, less doors and windows, with joint compound and the cost.

Change the values and press Calculate to work out your own figures.

Enter the room's size and choose the sheet size.

Size of this dimension.
Size of this dimension.
Size of this dimension.
What you're covering.
Width × length.
Total area of openings to leave out.
For waste, cuts or compaction; for example 10.
For the cost.
Result
Sheets
15 sheets
Area
472 sq ft (43.85 m²)
Sheet
4 × 8 ft (32 sq ft)
Joint compound
about 25 lb lightweight or 34.5 lb quick-set powder

You need 15 sheets.

Show the working
  1. sheets = area ÷ sheet area, rounded up

How to use it

Enter the room's size and choose the sheet size.

Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.

Key facts

sheets = (walls + ceiling − openings) ÷ sheet area, rounded up

Sheets

Hang sheets to minimize joints: 4 × 12 sheets on 8 ft walls laid horizontally leave one seam.

Questions

How many sheets of drywall for a 12 × 10 ft room?

15 sheets of 4 × 8 for the walls and ceiling (472 sq ft), before waste.

Reviewed by RK Calculator Team. Updated 2026-09-26.

Formulas

sheets = (walls + ceiling − openings) ÷ sheet area, rounded up

Sources

Limitations

  • Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
  • Tank results are the geometric volume; real tanks have wall thickness and fittings.

Formula version 0.1.0Reviewed