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.
- A 1/2” sheet is actually 15/32" thick.
- A 1/4” sheet is actually 7/32" thick.
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.