How many sheets of plywood do I need?
Plywood sheets for a wall, floor or project, counted by area with the waste allowance you set, in feet, inches or metres.
Sheet size
Feet, inches or metres, such as 12, 150 in, 3.6 m or 3600 mm. The extra for waste is your own allowance for offcuts and mistakes.
Sheets needed
3 sheets of 4 x 8
12 ft x 8 ft = 96 sq ft. 96 ÷ 32 sq ft a sheet = 3.
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How the count works
The area is the length times the width. Any extra you set for waste is added to it as a percentage, the total is divided by one sheet’s area, and a part sheet counts as a whole one. A 4 x 8 sheet covers 32 sq ft, a 4 x 9 covers 36 and a 4 x 10 covers 40.
Openings and offcuts
Doors, windows and other openings stay in the area and are counted as if covered. The area count is the fewest sheets that could cover the space, and offcuts too small to use elsewhere add to it.
Sheet size
Each sheet counts at its full stated size, such as 48" x 96". PS 1 lets a panel be up to 1/16" under the size its maker states, or 1/8" under when it’s marked sized for spacing, and the count leaves that out.
Floors and walls
Which thickness and grade a subfloor or wall needs comes from the panel’s span rating and your local building code, and your building department can say which applies.
Common questions
How many sheets of plywood for a 12 x 12 floor?
A 12 by 12 foot floor is 144 square feet, or 4.5 sheets of 4 x 8 at 32 square feet each, so 5 sheets before any extra for waste.
How many 4x8 sheets of plywood are in 100 square feet?
100 divided by 32 is 3.125, so it takes 4 sheets to cover 100 square feet.
Where we get our information from
The sheet size tolerances come from PS 1-22, section 5.10.1. Everything else is arithmetic on the sizes you enter. Checked against published data from NIST.
See all 1 source
- NIST, Voluntary Product Standard PS 1-22, Structural Plywood (2023)
This is a count by area. Check it against your own cut plan.