Count OSB or plywood sheets for a wall or gable roof, with openings and slope handled for you.
How it works
Wall area less openings, or roof footprint times the slope multiplier. Add waste and divide by 32 square feet per sheet.
Before you order
- Run long edges across the studs or rafters.
- Follow the nailing schedule on the panel or in your code.
- Leave the panel’s stated gap so sheets can expand.
Common questions
Should I subtract windows?
On walls, yes, because cutouts rarely get reused for anything large.
How do I handle hips and valleys?
Use the roofing calculator waste figure, because cuts increase on complex roofs.