Plywood Calculator

How the plywood calculator works

A full 4×8 sheet is 32 square feet. Divide your total surface area by 32, add a waste factor (10–20% for straight cuts, 25%+ for angled or curved cuts), and round up. Buy full sheets — most yards won't cut and refund partials.

Nominal vs actual plywood thickness

This trips up every new woodworker. A "3/4-inch" plywood sheet is almost never 0.750 in thick — it's usually 0.703 to 0.720 in. That 0.030–0.047 in gap breaks dado joints and throws off cabinet interiors. See our nominal vs actual guide for exact numbers, or use the cut list calculator which adjusts every interior part based on your caliper reading.

Common cabinet-grade plywood sizes

• 3/4 in nominal — actual ≈ 0.703 in (18 mm Baltic birch is 0.708 in)
• 1/2 in nominal — actual ≈ 0.472 in
• 1/4 in nominal — actual ≈ 0.203 in (common for cabinet backs)

Cabinet math example

A 48 in wide cabinet with two 3/4 in sides has an inside width of 48 − (2 × 0.703) = 46.594 in, not 46.500 in. That's a 3/32 in error — enough to make a shelf fall through. The calculator handles this for you.