20mm Or 30mm Quartz Worktop – Choosing The Right Thickness

A question that’s been coming up recently with kitchen design clients is; Should I have a 20mm or 30mm quartz worktop?

It might seem like a small detail but it’s the small details that can make some of the biggest impacts in kitchen design!

In this post, I’ll explain the factors to consider between 20mm and 30mm quartz worktops as well as the differences and impacts they can have on your kitchen design.

Let’s get into it!

๐Ÿ“‹ In a hurry? Here’s the key takeaway:

20mm Quartz: Offers a sleek, modern look. More affordable and suitable for contemporary kitchen designs.
30mm Quartz: Delivers a traditional, substantial feel. Ideal for classic kitchens and provides enhanced durability and strength for heavier use.

Read on to learn more…

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20mm vs 30mm quartz worktop

For this post, I’m honing in on quartz as the material of choice for kitchen worktops. (Honing ๐Ÿ˜‰ )

Quartz maintains its status as one of the most popular, if not the most popular, choice for kitchen worktops, and it’s the material I receive the most inquiries about.

As such, a common question that arises is about the optimal thickness for a quartz worktop, specifically, whether to choose 20mm or 30mm.

In the following sections, I’ll delve into various aspects, helping you make an informed decision for your kitchen project.


Quartz, known for its hardiness and longevity, is inherently a durable material regardless of thickness.

However, the thickness can have a subtle impact on its durability.

A 30mm quartz worktop, being thicker, naturally offers a bit more robustness and resistance to stress and strain.

This increased thickness lends itself to better handling of weight and impact, making it a suitable choice for areas in the kitchen that might see heavier use or need to support more weight.

In contrast, while 20mm quartz worktops are still remarkably durable, they are slightly less resistant to extreme forces compared to their 30mm counterparts.

This difference, though minimal in many cases, could be a deciding factor for kitchens where heavy-duty use is anticipated.

I think it’s worth stressing that the enhanced durability of a 30mm worktop doesn’t imply that a 20mm worktop is insufficient for most uses.

In reality, both thicknesses offer a high level of durability that meets the needs of most home kitchens.

30mm quartz worktop in traditional shaker kitchen deVOL
30mm Quartz worktop with a traditional shaker kitchen
Image – deVOL

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20mm quartz worktops are known for their sleek, contemporary look.

A thinner 20mm profile offers a more streamlined and modern aesthetic, making them a popular choice in contemporary kitchen designs.

On the other hand, a 30mm quartz worktops present a more substantial and robust appearance.

This thickness imparts a sense of solidity and traditional elegance, often preferred in classic or larger kitchen settings.

A 30mm worktop can provide a commanding presence and is especially well-suited for kitchens with a grander scale or a more traditional design.

The thickness of the quartz worktop also impacts the possibilities for edge detailing.

With 30mm worktops, there’s more material to work with, allowing for more ornate and elaborate edge designs. This can be a significant aesthetic advantage if youโ€™re looking for a more customized, detailed look.

20mm worktops, while still offering various edge options, may not be able to give you quite as ornate edge details.

While it’s usually my go-to rule for certain design styles, 20mm for modern and 30mm for traditional, it’s important to remember that these are not strict rules.

Some may prefer the bold statement of a 30mm worktop in a modern kitchen, or the subtlety of a 20mm worktop in a classic setting.

Ultimately, the choice should reflect your style and the specific aesthetics of your kitchen space.


Typically, 30mm quartz worktops are more expensive than their 20mm counterparts.

The increased cost can be attributed to the larger amount of material used and the additional processing required for the thicker slabs.

The price difference, in percentage terms, can vary depending on the manufacturer, the quality of the quartz, and the complexity of the installation.

On average, you can expect a 10-20% price increase for 30mm worktops compared to 20mm ones.

However, this is a general estimate and prices can vary widely based on the factors mentioned.

Additional Cost Implications

Beyond the base price of the material, there are other cost considerations to take into account:

  1. Upstands and Backsplashes: Typically, upstands and backsplashes use 20mm thick quartz. If you choose a 30mm worktop, you might face the need to purchase additional slabs for these elements.

    This is because a 30mm slab may not yield as many usable cut-offs for backsplashes or upstands as a 20mm slab would. This can lead to higher material costs.

  2. Installation Costs: Thicker worktops are heavier and can be more challenging to handle and install, potentially increasing labour costs.

    Additionally, the cabinetry and support structures may need to be stronger to support the extra weight of a 30mm worktop, which can add to the overall cost.

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Structural Integrity

Both 20mm and 30mm thicknesses offer robustness, but there are differences in their structural capabilities and design possibilities that might influence your decision.

The main one is their unsupported overhang limits.

A 30mm thick worktop typically allows for a longer unsupported overhang, up to about 30cm.

Which is ideal for seating areas or kitchen islands where you might want an overhanging countertop for stools or chairs.

In comparison, a 20mm worktop generally supports up to a 25cm overhang.

This difference is due to the increased strength and stability provided by the additional thickness in the 30mm worktops.

30mm thick quartz with a 30cm unsupported overhang
30mm thick quartz with a 30cm unsupported overhang

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When it comes to the maintenance of quartz worktops, both 20mm and 30mm thicknesses are known for their ease of upkeep and maintenance.

Quartz is a non-porous material, making it pretty resistant to staining and easy to clean. Regular maintenance typically involves wiping the surface with a damp cloth and a mild detergent.

This easy maintenance characteristic is consistent across both 20mm and 30mm thicknesses, meaning that the difference in thickness does not significantly impact any maintenance concerns.

Both options offer the same level of convenience and efficiency in upkeep, ensuring that your kitchen remains both functional and aesthetically pleasing with minimal effort, regardless of the thickness you choose

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Creating cut-outs for installations like hobs, cooktops, and sinks is a critical step in fitting a quartz worktop. The thickness of the quartz, whether 20mm or 30mm, can play a role in how these cut-outs are handled.

Strength and Stability Around Cut-Outs

30mm Quartz Worktops: These thicker worktops provide a greater amount of material around the cut-outs. This extra material can be crucial for enhancing the strength and stability required for heavy or large fixtures like sizable sinks or substantial cooktops.

The robustness offered by the 30mm thickness ensures that these installations are well-supported and secure.

20mm Quartz Worktops: While perfectly capable of accommodating standard sinks and hobs, 20mm worktops have less material surrounding the cut-outs.

This doesnโ€™t pose a problem for most installations, but it’s something to consider if you plan to install particularly heavy or large fixtures, or have multiple cut-outs in a single length of countertop.

Sink and tap cut out in 20mm quartz worktop

Design and Installation Flexibility

30mm Worktops: The additional thickness affords more leeway in terms of cut-out design and the types of installations that can be supported. For example, some hob designs may necessitate a certain depth for optimal installation, a requirement more easily met with the 30mm thickness.

20mm Worktops: There are specific instances where 20mm worktops might face limitations. A common example is the installation of a hob above a built under double oven.

The thinner profile of 20mm quartz may not provide adequate clearance as required by some appliance designs.

It’s important to consult with the hob and oven manufacturer and adhere to their installation guidelines to ensure the worktop thickness is suitable and safe for your intended setup.

Depending on your cabinet size and style, sometimes this isn’t an issue. Always check though!

Built under double oven installation guide with hob above worktop thickness guide
Installation guide for a built-under double oven with a hob above

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Is a 20mm or 30mm quartz worktop better?

When it comes to choosing between a 20mm and a 30mm quartz worktop, the answer isn’t a straightforward ‘better or worse’ scenario. Instead, it depends on a range of factors.

However, If I’m being honest, it’s mostly down to the look (and sometimes the cost).

If you prioritize a modern aesthetic and cost-effectiveness, a 20mm worktop may be more suitable.

Conversely, if you prefer a more traditional and substantial look, want slightly larger unsupported overhangs, or require a more elaborate edge detail, a 30mm option might be the better choice.

If in doubt, visit a kitchen showroom and see both thicknesses on display. You’ll soon know which one you prefer! ๐Ÿ‘


is 20mm quartz strong enough for a breakfast bar?

Yes, 20mm quartz is strong enough for a breakfast bar.

The typical maximum overhang for 20mm thick quartz is around 25cm, which is fine for casual dining or sitting and chatting for most.

You might bump your knees if you’re particularly tall. ๐Ÿ˜‚

Can the Thickness of a Quartz Worktop Affect Its Colour and Finish Options?

The thickness of a quartz worktop typically does not limit the colour and finish options available.

Both 20mm and 30mm worktops are available in a wide range of colours and finishes, from polished to matte and everything in between.

The manufacturing process of quartz allows for consistent colour and pattern throughout the material, regardless of its thickness.



Michael from

Michael is a kitchen designer from the UK. He's been designing and project managing new kitchen installations for over 10 years. Before that, he was an electrician and part of a team that fitted kitchens. He created Kitchinsider in early 2019 to help give people advice when it comes to getting a new kitchen.