Actual Thickness of of Plywood

Plywood is often sold in 1/4", 1/2", or 3/4" nominal thicknesses, but the actual thickness is often 1/32" thinner. Because the actual thickness may vary, measuring the plywood sheet using a caliper is the only accurate way to determine its thickness.

• A 3/4” sheet is actually 23/32" thick... Caliper shows between 0.688 - 0.719
• A 1/2” sheet is actually 15/32" thick... Caliper shows between 0.440 - 0.469
• A 1/4” sheet is actually 7/32" thick... Caliper shows between 0.200 - 0.219

The exception to this rule is plywood sheets that are over an inch thick. 1-1/4" and 1-1/8" plywood sheets are generally true sizes and not nominal.

Wood shrinks as it dries and moisture leaves the wood. This means that a sheet of plywood that started at 3/4” may shrink slightly after manufacturing. The glue between the plies will swell the wood slightly during manufacturing; it will then shrink as it dries. Plywood is almost always thinner than the nominal measurement due to the fact that most tooling in furniture and cabinet factories and manufacturing facilities can accommodate plywood that is thinner than expected but not thicker than expected.