Understanding 4/4 vs 8/4 Lumber for Woodworking Projects

If you have ever shopped for hardwood lumber and seen thickness listed as 4/4 or 8/4, you are not alone in wondering what it actually means. These labels are common in woodworking, but they can feel confusing when you are trying to figure out what size board to buy for your project.

This guide breaks down the difference between 4/4 and 8/4 lumber, what those thickness labels mean, and when each one makes the most sense for furniture, shelves, cutting boards, table tops, and other woodworking projects.

What Does 4/4 and 8/4 Mean?

In hardwood lumber, thickness is often described in quarter-inch increments. That is where terms like 4/4 and 8/4 come from.

• 4/4 means four quarters of an inch, or roughly 1" thick in rough form.
• 8/4 means eight quarters of an inch, or roughly 2" thick in rough form.

The important part is that these are rough lumber thickness references, not always the final finished thickness after drying, planing, and surfacing.

Why the Final Thickness Is Usually Smaller

Once rough lumber is dried and surfaced, it loses some thickness. That means a board sold as 4/4 will usually finish at .75" (3/4") thick, and a board sold as 8/4 will usually finish up at 1.75" thick.

This is one of the main reasons woodworkers get confused when ordering lumber online. The listed lumber thickness tells you the starting category, but the final usable thickness depends on how the board is milled and prepared.

If you want project-ready material that is closer to a finished size, take a look at:

• Dimensional Lumber
• Dimensional Lumber Guide
• S4S vs. Rough Lumber

4/4 vs 8/4 at a Glance

When to Use 4/4 Lumber

4/4 lumber is one of the most useful and common hardwood thicknesses for woodworking. It works well when you do not need especially thick final parts and want material that is versatile, easier to work with, and often more cost-effective than thicker stock.

4/4 is commonly used for:

• Cabinet parts
• Shelves
• Boxes
• Charcuterie boards
• Cutting boards
• Table aprons
• Panel glue-ups
• General furniture components

Browse common 4/4-friendly project material here:

• Shop Dimensional Lumber
• Shop Maple
• Shop Walnut
• Shop Cherry
• Shop Live Edge Charcuterie Stock

When to Use 8/4 Lumber

8/4 lumber makes more sense when you want thicker finished parts or you need extra material to mill down into substantial-looking components. It gives you more room to shape, flatten, and surface the stock while still ending up with a thicker final part.

8/4 is commonly used for:

• Table tops with more visual weight
• Bench tops
• Furniture legs
• Chunky shelves
• Island tops
• Work surfaces
• Heavier statement pieces

Helpful thicker-stock options:

• Walnut 1.75" Thick
• White Oak 1.75" Thick
• Cherry 1.75" Thick
• Maple 1.75" Thick
• Walnut Panels
• White Oak Panels

How to Choose Between 4/4 and 8/4

1. Start with Your Final Finished Thickness

The best choice usually starts with the thickness you want the finished part to be. If your finished part does not need to be especially thick, 4/4 is often enough. If you want a thicker, heavier-looking finished piece, 8/4 is usually the better route.

2. Think About the Visual Style

Thicker stock changes the look of a project. A chunky shelf, heavy table top, or substantial bench can feel much more premium when built from thicker material. If the project is meant to feel sleek and lighter, 4/4 may be all you need.

3. Think About Milling and Waste

Thicker stock gives you more room to flatten and surface boards while still keeping a thicker finished result. That can be useful for larger parts, but it also usually means spending more on material.

4. Match the Lumber to the Project Type

A cutting board, drawer front, or shelf stock piece often does not need 8/4 thickness. A bench top, thick shelf, or large furniture leg often benefits from it.

Best Uses by Project Type

• Cutting boards and charcuterie boards: usually 4/4
• Shelves: often 4/4, sometimes 8/4 for thicker floating shelves
• Dining tables: depends on the look you want
• Coffee tables: either can work depending on design
• Benches: often 8/4 for tops or heavier visual weight
• Furniture legs: often 8/4
• Boxes and smaller projects: usually 4/4

Common Mistakes When Buying Lumber Thickness

• Assuming 4/4 means the board will finish at a full 1"
• Assuming 8/4 will always be exactly 2" finished
• Buying thicker stock when the project does not actually need it
• Buying thinner stock and not leaving enough room for milling
• Ignoring whether the lumber is rough, surfaced, or already project-ready

Helpful Guides and Products

• Dimensional Lumber Guide
• S4S vs. Rough Lumber
• Board Foot Guide
• Hardwood Species Guide
• Browse All Wood Collections

Frequently Asked Questions

What does 4/4 lumber mean?

4/4 lumber means the board started at roughly 1" thick in rough form before drying and surfacing.

What does 8/4 lumber mean?

8/4 lumber means the board started at roughly 2" thick in rough form before drying and surfacing.

Is 8/4 lumber exactly twice as thick as 4/4?

In rough terms, yes. But once both boards are surfaced, the final thickness is usually a bit less than the rough starting size.

When should I use 8/4 instead of 4/4?

Use 8/4 when you want thicker finished parts like legs, thick shelves, bench tops, or heavier furniture details.

Is 4/4 lumber good for furniture projects?

Yes. 4/4 is very common for furniture, shelves, boxes, panels, charcuterie boards, and many other woodworking projects.