Drywall estimator

Did you know?

Drywall is sold as big sheets, but your walls are full of small surprises: soffits, closets, windows, doors, weird angles, and the fact that every cut produces scrap. The “right” sheet count is the one that lets you finish without a midnight run for two more panels.

Standard: 8' × 4' (32 sq ft). Also available: 12' × 4', 10' × 4'.
Typical: 10-15% for cuts and mistakes.
12 sheets
10.00 sheets needed (includes 15% waste)
Area to cover
320 sq ft
Sheet size
8' × 4' (32 sq ft)
For developers: API access

Same result via GET request (use current inputs above):

curlcurl -s "https://howdeedo.com/api/calc/drywall-estimator?areaSqFt=320&sheetLengthFt=8&sheetWidthFt=4&wastePercent=15"
fetchfetch("https://howdeedo.com/api/calc/drywall-estimator?areaSqFt=320&sheetLengthFt=8&sheetWidthFt=4&wastePercent=15").then(r => r.json())

Get an API key for higher limits and stable access.

Good to know

Sheet size is a strategy decision. 4×12 sheets reduce seams (less taping) but are heavier and harder to maneuver. 4×8 sheets are easier in tight spaces but create more joints. Your body and your room layout are part of the math.

Corners create scraps. The more corners, doors, and windows you have, the more offcuts you produce. A perfectly rectangular room is drywall heaven. A room with bump-outs is where the waste factor earns its keep.

Ceilings are where it gets real. Hanging drywall overhead is harder, and the seams matter more visually. If you’re including ceilings, consider using larger sheets to reduce joints — and plan your lift/help accordingly.

Methodology, disclaimers & sources

How it works

  • Total area (sq ft) ÷ sheet area (sq ft per sheet) = raw sheets
  • Add waste/overage if enabled
  • Round up to whole sheets

Details & assumptions

This is an area-based estimate. It doesn’t model stud layout, optimal cutting patterns, or special situations (like angled ceilings) unless you add extra area manually. Waste accounts for offcuts and layout inefficiency.

More facts

Frequently asked questions