Free Tool
Free plywood and sheathing calculator
Enter the area and sheet size and get the number of plywood or OSB sheets and fasteners, with a waste allowance built in. Free, no signup.
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Count the sheets before the delivery
Wall, roof, and floor sheathing all come down to sheet count. Enter the area you are covering and the sheet size, and the calculator gives you the sheets with waste already added.
For a job with several planes, like a roof with two slopes or a house of walls, add the areas together or run each one and total the sheets. Odd angles and hips eat more material, so lean toward the higher waste number on a cut-up job.
Fasteners are the part people forget to order. A typical nailing schedule is about every 6 inches on the panel edges and 12 inches in the field, which works out to roughly 60 fasteners per sheet. The calculator estimates that so you are not short a box on the last wall.
Bigger sheets cover faster and leave fewer seams to block and tape, but they are heavier to handle, so match the size to your crew and the lift.
Plywood & Sheathing Calculator questions
How many sheets of plywood do I need?
Divide the area by the coverage of one sheet, add waste, and round up. The calculator does it for 4x8, 4x9, and 4x10 sheets.
How many fasteners per sheet?
About 60 with a common schedule of 6 inches on the edges and 12 in the field. The calculator estimates the total.
Plywood or OSB?
Both cover the same area, so the sheet count is the same. Pick the panel your job and budget call for.
Is this really free?
Yes. No email, no signup, and nothing you type leaves your browser.
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Disclaimer: These free tools and templates are provided for general information and estimating purposes only. All results — including quantities, material and cost estimates, load, sizing, and span figures, scores, and any guidance or warnings — are rough approximations that may not fit your specific project, site conditions, local building codes, or current prices. They are not engineering, architectural, structural, legal, financial, or other professional advice, and are not a substitute for a licensed engineer, architect, contractor, or other qualified professional. Always confirm quantities, sizing, and structural, electrical, mechanical, and code requirements with a licensed professional and your local authority having jurisdiction before purchasing materials or performing any work. Werx makes no warranty as to accuracy and accepts no liability for any decision made using these tools. Use at your own risk. See our Terms of Service.