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What Thickness of Plywood Do I Need?


What Thickness of Plywood Do I Need?

Not sure whether you need 6mm, 9mm, 12mm, 15mm or 18mm plywood? Use our thickness finder to compare the most common plywood thicknesses and see what each is generally used for.

Select a thickness below to see its typical applications, indicative weight, relative rigidity and the type of project it may suit.

Choose a Plywood Thickness

Tap a thickness to see more information.

3mm Plywood

3mm plywood is one of the thinner plywood options and is generally chosen where low weight and easy cutting are more important than structural rigidity.

Indicative 8 x 4 weight Approx. 5kg
Rigidity Very low
Best for Lightweight panels
Typical choice Craft & lining

Typical uses

  • Lightweight panels
  • Model making
  • Craft projects
  • Backing panels
  • Decorative work
  • Small components

Consider a thicker sheet if...

You need the plywood to span unsupported areas, carry loads, take repeated fixings or provide meaningful structural rigidity.

Common alternative: 4mm or 6mm plywood.

Shop 3mm Plywood

4mm Plywood

4mm plywood provides more rigidity than very thin plywood while remaining relatively light and easy to handle.

Indicative 8 x 4 weight Approx. 6–8kg
Rigidity Low
Best for Light joinery
Typical choice Lining & panels

Typical uses

  • Cabinet backs
  • Drawer components
  • Lightweight lining
  • Small furniture components
  • Vehicle interiors
  • Backing and panels

Consider a thicker sheet if...

You need better screw holding, increased stiffness or a panel that will be subject to heavier loads.

Common alternative: 6mm plywood.

Shop 4mm Plywood

6mm Plywood

6mm plywood is a popular lightweight sheet for lining, furniture components and projects where some rigidity is needed without using a heavy board.

Indicative 8 x 4 weight Approx. 9–12kg
Rigidity Low–medium
Best for Lining & components
Popular grades Marine & hardwood

Typical uses

  • Van lining
  • Trailer lining
  • Wall and ceiling panels
  • Furniture components
  • Cabinet backs
  • Lightweight partitions
  • General joinery

Why choose 6mm?

6mm is often a good step up from thin plywood when you want more stiffness without moving to a much heavier sheet.

Consider 9mm where greater rigidity or more substantial fixing is required.

Shop 6mm Plywood

9mm Plywood

9mm plywood is a useful mid-range thickness for lining, joinery, furniture components and applications requiring more rigidity than thinner plywood.

Indicative 8 x 4 weight Approx. 13–17kg
Rigidity Medium
Best for General joinery
Popular grades Marine & hardwood

Typical uses

  • Van lining
  • Furniture
  • Shelving
  • Cabinet construction
  • Wall lining
  • General joinery
  • Workshop projects

Why choose 9mm?

9mm offers a useful balance between weight and stiffness and is often a practical choice when 6mm feels too flexible.

Consider 12mm where the panel needs additional rigidity or more substantial fixing.

Shop 9mm Plywood

12mm Plywood

12mm plywood is a versatile thickness for furniture, joinery, shelving, lining and many general-purpose projects.

Indicative 8 x 4 weight Approx. 18–23kg
Rigidity Medium–high
Best for Furniture & joinery
Popular grades Marine & hardwood

Typical uses

  • Furniture
  • Shelving
  • Cabinet components
  • Van interiors
  • Worktops and work surfaces
  • Joinery
  • General fabrication

Why choose 12mm?

12mm is a good all-round thickness where you want a reasonably rigid panel without the additional weight of 15mm or 18mm plywood.

Consider 15mm for larger unsupported panels or when increased rigidity is important.

Shop 12mm Plywood

15mm Plywood

15mm plywood provides a useful balance of rigidity, strength, weight and workability. It is a popular thickness for furniture, joinery and fabrication.

Indicative 8 x 4 weight Approx. 22–29kg
Rigidity High
Best for Furniture & joinery
Popular grades Marine & hardwood

Typical uses

  • Furniture
  • Cabinet construction
  • Shelving
  • Van lining
  • Joinery
  • Shopfitting
  • General fabrication

Why choose 15mm?

15mm is a useful middle ground when 12mm may not provide enough rigidity but 18mm would add unnecessary weight or thickness.

Consider 18mm where additional stiffness and strength are important.

Shop 15mm Plywood

18mm Plywood

18mm plywood is one of the most useful thicker plywood options for substantial joinery, furniture, flooring and demanding fabrication applications.

Indicative 8 x 4 weight Approx. 27–35kg
Rigidity Very high
Best for Heavy-duty panels
Popular grades Marine & hardwood

Typical uses

  • Furniture
  • Heavy-duty shelving
  • Flooring applications
  • Workbenches
  • Construction
  • Joinery
  • Vehicle floors
  • General fabrication

Why choose 18mm?

18mm is a common choice when a thicker, stiffer sheet is required and weight is less of a concern.

Consider 15mm if you want to reduce weight and the application allows a thinner panel.

Shop 18mm Plywood

22mm Plywood

22mm is a substantial plywood thickness for projects requiring a thick, rigid panel. Availability can vary by plywood type and specification.

Indicative 8 x 4 weight Approx. 33–43kg
Rigidity Very high
Best for Heavy panels
Availability Selected ranges

Typical uses

  • Heavy-duty furniture
  • Thick shelving
  • Heavy fabrication
  • Specialist joinery
  • Applications requiring additional panel thickness

Could 18mm be enough?

22mm adds thickness and rigidity but also increases weight. If the application does not require the additional thickness, 18mm may provide a more practical balance.

Common alternative: 18mm or 25mm depending on the application.

View 22mm Plywood

25mm Plywood

25mm plywood is a heavy-duty sheet option where substantial thickness and rigidity are required. It is available in hardwood and marine plywood options at Plywood Etc.

Indicative 8 x 4 weight Approx. 37–48kg
Rigidity Very high
Best for Heavy-duty work
Popular grades Marine & hardwood

Typical uses

  • Heavy-duty flooring
  • Heavy furniture
  • Workbenches
  • Structural applications where specified
  • Heavy fabrication
  • Marine applications using suitable BS1088 plywood

Do you really need 25mm?

25mm plywood is substantially heavier than 18mm. If the project does not require the additional thickness or rigidity, 18mm may be a more practical option.

Common alternative: 18mm or 22mm plywood.

Shop 25mm Plywood

Plywood Thickness Comparison

Thickness Indicative 8 x 4 weight Relative rigidity Typical applications
3mm Approx. 5kg Very low Craft, backing and lightweight panels
4mm Approx. 6–8kg Low Cabinet backs, lining and light joinery
6mm Approx. 9–12kg Low–medium Van lining, panels and components
9mm Approx. 13–17kg Medium Joinery, furniture and lining
12mm Approx. 18–23kg Medium–high Furniture, shelving and joinery
15mm Approx. 22–29kg High Furniture, joinery and fabrication
18mm Approx. 27–35kg Very high Heavy-duty joinery and flooring
22mm Approx. 33–43kg Very high Heavy panels and specialist applications
25mm Approx. 37–48kg Very high Heavy-duty work and specialist applications

Still Not Sure Which Thickness to Choose?

Start with the job, not the thickness.

If you are lining something or need a lightweight panel, start around 4–6mm. For general joinery and furniture, 9–15mm is often the useful range. For substantial furniture, flooring or heavier fabrication, look towards 18mm and above.

Remember that thickness alone does not determine whether plywood is suitable. Plywood grade, veneer construction, moisture resistance, span, support and loading all matter.

Other Plywood Guides

Need to choose the plywood type?

Compare marine, hardwood, birch and other plywood types before choosing your sheet.

Explore All Plywood →

Need the right sheet size?

We stock a wide range of plywood dimensions, including full 8 x 4 sheets and smaller handy sizes.

Browse Hardwood Plywood Sizes →

Plywood Thickness FAQs

What is the best thickness of plywood?

There is no single best thickness. The right thickness depends on the application, span, support, loading, plywood grade and required weight. For general furniture and joinery, 9mm to 18mm covers many applications, while thinner sheets are useful for lightweight panels and thicker sheets for heavier-duty work.

Is thicker plywood always stronger?

Thickness generally increases panel stiffness, but plywood grade and construction also affect performance. A thicker non-structural panel should not automatically be assumed to be suitable for a structural application.

Is 6mm plywood strong enough for van lining?

6mm plywood is commonly used for lightweight van and vehicle lining where appropriate. The best thickness depends on the area being lined, fixing method, expected impact and the finish required.

Is 9mm plywood stronger than 6mm?

Generally, yes. Increasing thickness substantially increases a panel's resistance to bending, although actual performance depends on the plywood construction and how the panel is supported.

Is 12mm plywood good for furniture?

12mm plywood is commonly used for furniture components, shelving and joinery. Whether it is suitable depends on the dimensions, design and loading of the individual component.

Should I use 15mm or 18mm plywood?

15mm can provide a useful balance between rigidity and weight, while 18mm provides greater thickness and stiffness. If the project can use 15mm without compromising the required performance, it may reduce weight.

What is the thickest plywood available?

Plywood is manufactured in a wide range of thicknesses, with availability depending on the plywood type and supplier. Plywood Etc currently offers plywood ranges including 18mm and 25mm, with selected thicker options also available.

Does plywood thickness affect weight?

Yes. For the same sheet dimensions, a thicker plywood sheet contains more material and will normally weigh more. Actual weight varies according to the plywood species, construction and density.

Important: Weight figures shown are indicative estimates for a nominal 2440 x 1220mm sheet. Actual plywood weight varies by species, veneer construction, moisture content and manufacturer. Rigidity descriptions are general guidance and should not be used as structural design calculations. Always check the manufacturer's technical information for your specific product and application.

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