Drywall / Plasterboard Calculator
Calculate sheets needed for walls and ceilings.
CACalifornia Building Code (Title 24)
References & Sources
Standards Cited
- ASTM C1396 — ASTM C1396: Standard Specification for Gypsum Board
Defines standard drywall sheet sizes, thicknesses, and material specifications for North American construction - GA-216 — Gypsum Association GA-216: Application and Finishing of Gypsum Panel Products
Provides guidance on drywall installation, fixing centres, and joint treatment
Formulas Used
- Wall Area:
wallArea = wallLength x wallHeight
Source: Standard geometry - Net Area:
netArea = wallArea - openingArea
Source: GA-216 - Sheets Required:
sheets = ceil(netArea / sheetArea)
Source: GA-216 - Sheet Area:
sheetArea = (sheetWidth / 1000) x (sheetHeight / 1000)
Source: ASTM C1396 — Standard sheet: 4x8 ft (1219x2438mm) = 2.97 m² - Screws per Sheet:
screws = sheetsRequired x fixingsPerSheet x 1.1
Source: GA-216 — Default 40 fixings per sheet with 10% extra; typical fixing centres 300mm at edges, 300mm in field - Joint Tape:
jointTape = sheetsRequired x 3m
Source: GA-216 — Approximately 3m of joint tape per standard sheet
Key Assumptions
- Standard drywall sheet size is 4x8 ft (1219x2438mm); also available in 4x10 and 4x12 — ASTM C1396 / GA-216
- Standard wall board thickness is 1/2" (12.7mm); ceiling/fire-rated is 5/8" (15.9mm) — ASTM C1396
- Default 40 fixings (screws) per standard sheet at recommended centres — GA-216
- Default 10% wastage for cuts and fitting around openings — Industry standard practice