What are standard plywood sizes?

The most common standard plywood size is 4x8 feet (1220x2440mm). Other common sizes include 5x5 feet (often used for Baltic Birch), 4x4 feet, and 2x4 feet (often called project panels).

Why is plywood thinner than its nominal size?

Plywood is thinner than its nominal size due to the sanding and finishing process during manufacturing, as well as the drying of the wood veneers. For example, a nominal 3/4-inch sheet actually measures around 23/32 inches (approx. 18mm).

What plywood thickness do I need for cabinets?

For cabinet boxes (carcases), 3/4-inch (18mm) or 5/8-inch (15mm) plywood is highly recommended for strength. For cabinet backs or drawer bottoms, 1/4-inch (6mm) is typically sufficient.

Plywood Sizes & Thickness Chart

Your complete reference for standard plywood dimensions. Whether you are building cabinets, framing a house, or making furniture, knowing the exact dimensions and grades of your sheet goods is the first step to a successful project.

Standard Plywood Sheet Sizes

When planning a project, the overall dimensions of your sheet goods dictate how parts can be nested and cut. Here are the most common standard sizes you will encounter at lumberyards and home centers:

Nominal Size (Imperial)	Actual Size (Metric)	Common Uses
4 × 8 ft	1220 × 2440 mm	The universal standard for construction and cabinetry.
5 × 5 ft	1525 × 1525 mm	Standard for Baltic Birch and premium cabinet plywood.
4 × 4 ft	1220 × 1220 mm	Half-sheets. Convenient for smaller projects and transport.
2 × 4 ft	610 × 1220 mm	Quarter-sheets (project panels). Ideal for small DIY tasks.

Plywood Thickness: Nominal vs Actual

One of the most common mistakes in woodworking and cabinetry is assuming a sheet of plywood is exactly its stated (nominal) thickness. Due to sanding, finishing, and the drying process, plywood is almost always slightly thinner than the label suggests.

Nominal Thickness	Actual Thickness (approx. inches)	Actual Thickness (approx. mm)
1/4"	0.205" - 0.234"	5.2 mm - 6.0 mm
3/8"	0.354"	9.0 mm
1/2"	0.451" - 0.468"	11.5 mm - 12.0 mm
5/8"	0.578" - 0.593"	14.7 mm - 15.0 mm
3/4"	0.703" - 0.718"	17.9 mm - 18.0 mm
1"	0.953"	24.2 mm

Pro Tip: Always measure your specific batch of plywood with calipers before cutting dados or grooves. Using a standard 3/4-inch router bit on a 23/32-inch sheet will result in a loose, sloppy joint.

Common Plywood Grades

Plywood is graded based on the quality of its face and back veneers. The front face receives a letter grade (A being the best), and the back face receives a separate letter.

A Grade: Premium quality. Smooth, sanded surface with no knots or repairs. Ideal for visible furniture parts and cabinet doors.
B Grade: Good quality. Solid surface, but may contain minor repairs (like football-shaped patches) or tight knots up to 1 inch across.
C Grade: Utility quality. May contain tight knots up to 1.5 inches, discoloration, and small splits. Often used for subflooring or backing.
D Grade: Structural quality. Can feature large knotholes (up to 2.5 inches) and splits. Un-sanded and meant for hidden construction purposes.

Common combinations include AC (great face, rough back, good for cabinets attached to walls) and CDX (utility grade with exterior-rated glue for sheathing).

How to Choose the Right Plywood

Choosing the correct size, thickness, and grade depends entirely on your application:

Cabinet Carcases: 3/4" (18mm) or 5/8" (15mm) pre-finished birch or maple plywood.
Drawer Boxes: 1/2" (12mm) Baltic Birch for sides; 1/4" (6mm) for the bottom.
Shop Furniture / Jigs: 3/4" (18mm) MDF or lower grade (BC) plywood.
Subflooring / Sheathing: 5/8" or 3/4" CDX or OSB (Oriented Strand Board).

Frequently Asked Questions

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