Calculators/ Framing & Exterior/Plywood Sheathing Calculator
Plywood Sheathing Calculator
Sheets of plywood or OSB for walls, floors and roofs.
Plywood Sheathing Calculator
ft
ft
ft²
%
Sheathing is bought by the sheet and cut to fit a framing module, so the count rarely divides evenly. Ten percent waste covers the offcuts that are too small to land on a stud.
How this is calculated
- Area = length × width, minus large openings. Small windows are usually sheathed over and cut out afterwards.
- Divide by 32 square feet for a standard 4 × 8 sheet, then add waste and round up.
- Standard nailing is 6 inches on centre at panel edges and 12 inches in the field, roughly 60 nails per sheet.
Frequently asked questions
Plywood or OSB?
OSB costs less and is structurally equivalent for most sheathing. Plywood handles repeated wetting better, which matters on a roof deck in a wet climate.
Should sheathing run horizontal or vertical?
Vertically on walls ties top and bottom plates together and often removes the need for blocking. Roof decking runs perpendicular to the rafters.