Because the actual thickness may vary measuring the plywood is the only accurate way to determine its thickness.
Half sheet plywood size.
A 3 4 sheet is actually 23 32 thick.
Softwood plywood typically used for rough framing comes in 4 x 8 feet 1220 x 2438 millimeters sheets.
Chart represents most common plywood sheet sizes in inches imperial system and millimeters metric dimensions.
3 7 inch 11 32 inches.
Hardwood plywood comes also in abbreviated sheets measuring 2 by 2 2 by 4 and 4 by 4 feet while utility grade plywood comes in longer 4 by 10 foot sheets.
Even though with all variation often 3 4 19 mm nominal 23 32 thickness tongue and groove.
1 4 inch 7 32 inches.
1 2 inch 15 32 inches.
A 1 2 sheet is actually 15 32 thick.
5 8 inch 19 32 inches.
3 4 inch 23 32 inches.
The most common size for plywood sheets is 4 x 8 feet followed by 5 x 5 feet.
And the top layer needs to be sanded after the sheet is made.
For pricing and availability.
Severe weather 1 2 in common southern yellow pine plywood sheathing application as 4 x 8.
In fact all wood expands as it gets wet and shrinks as it dries.
Most of plywood sheets available in different thicknesses.
Plywood is often sold in 1 4 1 2 or 3 4 nominal thicknesses but the actual thickness is often 1 32 thinner.
Remember plywood is made from many layers of thin wooden sheets.
The most common plywood sheet dimension 4 feet by 8 feet translates to the metric dimensions of 1 219 by 2 438 millimeters.