Drywall Calculator
Estimate how many drywall sheets, screws, and how much joint tape you need for a room, based on wall area and a standard waste allowance.
Computed in your browser — nothing you enter is uploaded. Figures are presented in United States units and terminology, and each formula’s basis is cited under regulatory standards below.
Last verified 2026-08-26 · v1.1.0
The standard allowance most suppliers and estimating guides assume for ordinary work.
Estimated drywall needed
12 sheets (4x8 ft)
- Gross wall area
- 392 ft²
- Doors + windows area (subtracted)
- 51.13 ft²
- Net wall area
- 340.87 ft²
- Area with waste factor
- 374.96 ft²
- Joint tape needed
- 126.12 linear ft
- Drywall screws needed
- 384 screws
At the values currently entered, the result works out to 12 sheets (4x8 ft). Figures are shown in United States units and terminology; switch the market above if you are building elsewhere.
Estimated cost
$144 - $252
- Drywall sheet (material only)$144 - $252
Estimated national-average pricing, adjusted by a rough regional multiplier — not a quote and not verified for your specific location or supplier. Last verified 2026-08-25.
Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Regulatory standards & verification citations
- Standard drywall sheet size is 4 ft x 8 ft (32 sq ft / 2.973 m²) — the most common size sold for wall installation
- 10-15% waste factor is standard industry practice for rooms with doors, windows, and outlet cutouts
- Joint tape: approximately 370 linear ft per 1,000 sq ft of drywall area (common manufacturer/retail estimating rule); screws: approximately 32 per standard 4x8 sheet on 16 in o.c. framing