Plywood Sheet Sizes And Thickness
A nominal 3/4 inch plywood sheet actually measures 0.719 inches — a real 1/32 inch sanding loss on both faces, present on every size except the 3/8 inch step.
A "3/4-inch" plywood sheet is closer to 0.719" — a real, published, 1/32"-under figure that comes from the sanding pass every sheet of veneer-core plywood gets on both faces after glue-up, not from a manufacturing tolerance or a rounding shortcut.
Where the loss comes from, and why it isn't flat
Veneer plywood is built from thin layers glued cross-grain and pressed, then sanded on both faces to give a smooth, uniform surface for finishing and to true up any thickness variation from the layup itself. That sanding removes real material, and the loss is close to consistent in absolute terms across the standard thicknesses rather than scaling as a fixed percentage:
| Nominal | Actual (in) | Loss from nominal |
|---|---|---|
| 1/4" | 0.219 | 0.031" |
| 3/8" | 0.359 | 0.016" |
| 1/2" | 0.469 | 0.031" |
| 5/8" | 0.594 | 0.031" |
| 3/4" | 0.719 | 0.031" |
Most steps lose almost exactly 1/32" — a light double-sided sanding pass — except 3/8", which loses about half that, likely reflecting a thinner core layup that tolerates less sanding before compromising the face veneer.
Baltic birch is a different product with a different convention
Baltic birch plywood is specified and sold in true metric thickness rather than the nominal-inch convention above, and it's a genuinely different construction: void-free cross-banded birch veneer through the full thickness, versus the softwood-veneer-over-particleboard-adjacent core more common in home-center plywood. A "12mm" Baltic birch sheet measures 0.472" actual — noticeably different from a nominal 1/2" (0.469") sheet even though the two numbers look close, and Baltic birch sheets come in a 60" x 60" format rather than the standard 48" x 96" sheet, which matters for cut-list planning far more than the thickness difference does.
Board footage and weight for a full sheet
A standard 4' x 8' sheet is 32 square feet of surface. Using the site's typical assumed plywood density of 34 lb/ft³ (a commonly published range for softwood-veneer plywood; hardwood-veneer sheets run denser), a full sheet at true 3/4" (0.719") thickness weighs about 65.2 lb, and the same sheet at true 1/2" (0.469") weighs about 42.5 lb — see /answers/how-much-does-a-sheet-of-3-4-plywood-weigh/ for that specific figure worked through with its caveats, since actual density varies by species and layup more than thickness does.
Where the actual thickness matters most
Dado and rabbet joinery cut to house a plywood panel needs to be sized to the actual thickness, not the nominal one — sizing the groove to a plain nominal 3/4" leaves a plywood panel loose by about 1/32" per side, which is enough to show a visible gap or require shimming on an otherwise tight case joint. Cabinet-grade construction that relies on plywood panels for structural rigidity (case sides, shelving) should also be checked against the actual thickness when consulting a span or deflection reference, for the same reason solid dimensional lumber is — see /reference/nominal-vs-actual-2x6/ for how that same actual-vs-nominal gap plays out in solid stock loaded on edge, a related but not identical mechanism to a plywood panel loaded flatwise.
Grade and thickness are independent variables
A sheet's letter grade (A, B, C, D — covered in /reference/plywood-veneer-grades/) describes face-veneer appearance and defect allowance, completely independent of its thickness — a nominal 3/4" sheet is available across the full grade range, and picking a higher grade doesn't change the actual thickness math above at all. Don't conflate the two when reading a cut sheet or a supplier listing; a "3/4 BC" and a "3/4 AC" sheet measure the same and cost differently for reasons that have nothing to do with the numbers on this page.
Cut-list planning around the real sheet size
A full sheet's 48" x 96" nominal footprint is itself close to exact — unlike thickness, plywood manufacturers don't typically undersize the face dimensions the way they undersize thickness, so a cut-list optimizer working from 48" x 96" stock is safe using that figure directly, with a small allowance for blade kerf on every internal cut (see /reference/saw-blade-kerf-reference/ for typical kerf widths) and for a factory edge that may not be perfectly square on an inexpensive sheet. The cut list optimizer handles the kerf math directly rather than requiring you to pad the stock dimension by hand.
Other sheet goods use different rules entirely
MDF and OSB don't follow this same sanding-loss pattern — MDF in particular tracks its nominal thickness closely because it isn't sanded down from a veneer layup the way plywood is. See /reference/mdf-sheet-sizes-and-thickness/ and /reference/osb-sheet-sizes-and-thickness/ for those figures directly rather than assuming this page's numbers carry over; the mechanism producing plywood's actual-vs-nominal gap is specific to how veneer plywood is manufactured.