Plywood sheet sizes: what you actually get

Guide · Updated July 2026 · 5 min read

Plywood is sold by names, not measurements. A "4×8 sheet of ¾-inch birch" is genuinely 48″ × 96″ in length and width — but its thickness is almost certainly 23/32″, and that thirty-second of an inch will telegraph into every dado you cut for it. Planning a cut list around nominal numbers is one of the quietest ways a project drifts out of square.

Here are the standard sizes, the actual measurements, and how to plan around both.

Standard plywood sheet dimensions

Sheet size (nominal)	Dimensions (in)	Dimensions (mm)	Common uses
4 × 8 (standard)	48 × 96	1220 × 2440	Cabinets, furniture, sheathing — the default
5 × 5 (Baltic birch)	60 × 60	1525 × 1525	Drawer boxes, jigs, small furniture
4 × 4 (project panel)	48 × 48	1220 × 1220	Small projects; big-box "handy panels"
2 × 4 / 2 × 2 (project panel)	24 × 48 / 24 × 24	610 × 1220 / 610 × 610	Repairs, prototypes
4 × 10	48 × 120	1220 × 3050	Tall panels, commercial work

Length and width are usually true to name on domestic sheets. Baltic birch is the exception worth knowing: a "5×5" is metric at heart (1525 mm ≈ 60″), and metric-spec sheets sold as 4×8 can run a hair under 48″ × 96″.

Nominal vs. actual thickness

Thickness is where the names lie. Sanding at the mill takes plywood below its nominal callout, so most hardwood plywood measures 1/32″ under:

Nominal thickness	Typical actual	In millimeters
1/4″	7/32″	~5.5 mm
1/2″	15/32″	~12 mm
3/4″	23/32″	~18 mm
Baltic birch 18 mm	18 mm (true)	18 mm

Two practical consequences:

• Dados and grooves — cut a ¾″ dado for "¾″" plywood and the joint rattles. Size joinery from the measured stock, or use undersized plywood router bits.
• Stacked dimensions — anywhere thickness adds up (cabinet sides, partitions, applied ends), the 1/32″ shortfalls add up with it.

Planning parts around a 4×8 sheet

Since 48″ × 96″ is the canvas, some part sizes are simply friendlier than others:

• Parts at 23¼″ or less rip four to a strip of width across the 48″ dimension — after kerf. Full 24″ parts do not: three cuts consume ⅜″, so only 23⅞″-and-under yields four across.
• Standard base cabinet depths (23¼″ finished side) exist partly because they divide a sheet efficiently.
• Leave the factory edge out of your math: most builders trim ¼″–½″ from each factory edge before referencing it, effectively shrinking the usable sheet to roughly 47″ × 95″.

When a project mixes part sizes — sides, shelves, stretchers, drawer parts — finding the arrangement that wastes the least material stops being arithmetic and becomes optimization. That's the job of a plywood cutting calculator: give it the parts and the sheet size, and it returns the layout, the sheet count, and the offcuts you'll have left. If you're building the part list itself, start with how to make a cut list.

How many sheets do I need?

A rough first check is area: total part area ÷ sheet area (32 sq ft for a 4×8), then add 15–25% for kerf, grain constraints, and imperfect nesting. But area math can't tell you whether the parts actually fit — twenty narrow strips and one 40″ panel can have the same area and very different sheet counts. Run the layout before you buy.