Plywood Sheets Calculator

4×8 plywood sheets for a flat area.

Inputs

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Formula

sheets = ceil((L × W ÷ 2.97) × (1 + waste% / 100))

Surface length × width gives area; divide by 2.97 m² per standard 4×8 ft sheet, add waste, round up.

Worked example

A 5 m × 4 m subfloor is 20 m². At 2.97 m² per sheet that's 7 sheets before waste; with 10%, order 8 sheets of 18 mm ply for sheathing.

Where this can give the wrong answer

  • Marine and structural ply have the same sheet size math — different span ratings.
  • Staggered joints need longer edge support — waste 10% minimum on big platforms.
  • Metric 1.2×2.4 m sheets match 4×8 ft area closely — same 2.97 m² assumption.

FAQ

Same area calculation — pick the material after you know sheet count.