How to Cut an Opening Larger in Quartz Countertop


Quartz countertops are extremely popular in kitchens and bathrooms due to their durability, aesthetics, and low maintenance. However, sometimes you may need to cut a larger opening in an existing quartz countertop to accommodate a new sink or cooktop. Cutting into quartz can seem intimidating, but with the right tools and techniques, it is very doable as a DIY project.

In this comprehensive guide, we will walk you through all the steps and considerations for cutting a larger hole in a quartz countertop. We will cover how to measure and mark the opening, what tools work best, how to make the cut, and how to finish the edges of the cutout smoothly and seamlessly. With proper planning and care, you can enlarge an opening in your quartz countertop and end up with a professional-looking result.

How to Cut an Opening Larger in Quartz Countertop

Step 1: Measure and Mark the New Opening Size

The first step is to determine the dimensions of the enlarged opening you need to cut based on the new sink or cooktop. Refer to the specifications of the new fixture and measure the existing hole that needs to be made bigger.

  • Mark the new length and width dimensions clearly on the countertop with a pencil. Use a ruler or tape measure to ensure accurate markings.
  • Mark an outline just inside the dimensions – this will be your cutting line.
  • Double check all measurements before proceeding! It is better to take extra time at this stage to avoid any expensive mistakes later on.

Step 2: Protect the Surrounding Area

Cutting quartz produces a lot of dust and debris. To keep the rest of your countertop protected:

  • Cover surrounding areas with plastic sheeting and painter’s tape.
  • You may also want to stuff rags into the sink hole to prevent dust getting inside.
  • Have a vacuum ready to contain dust and shards as you cut.

Step 3: Use the Right Tools

Cutting a precise opening in quartz requires specialty tools designed for smooth edges:

  • A 4-inch angle grinder with a diamond blade. Look for one specifically made for cutting stone/quartz. This will handle most of the cutting.
  • A quartz-cutting bit for a rotary hand tool like a Dremel. This is for finer detail work.
  • Safety gear – goggles, ear protection, gloves, and a dust mask. Quartz cutting generates lots of debris and noise.

Step 4: Make Relief Cuts

Once your lines are marked, it’s time to start cutting. Do NOT try cutting out the entire opening in one go:

  • Make small relief cuts first along the inside corners of your marked outline.
  • Cut at 45 degree angles toward the center of the outline. This removes some interior quartz and creates space for the blade.
  • Use the angle grinder for straight sections and Dremel for tight corners.

Step 5: Cut Along the Outline

Now you can begin cutting along your marked opening outline:

  • Work slowly and steadily for clean cuts. Apply light but firm pressure.
  • Cut 2-3 inches depths maximum to avoid cracking the slab.
  • Periodically dip your blade into water to keep it cool.
  • Make several passes along the cut line to gradually deepen the cut.
  • Use the Dremel for any touch up cuts needed.

Step 6: Check Fit and Adjust as Needed

With the bulk of the cut done, check that your new opening size fits the sink/cooktop specifications:

  • Carefully lift out the cutout piece and set aside.
  • Place your new sink or cooktop into the enlarged hole.
  • Look for any tight spots and use the grinder or Dremel to shave down edges as needed for a smooth fit.

Step 7: Smooth and Finish the Cut Edges

For a seamless look, you need to smooth over the rough cut edges around the enlarged opening:

  • Use 100-150 grit sandpaper to gently sand cut edges of the countertop opening.
  • Focus on smoothing any major ridges or uneven areas so edges are flush.
  • Finish with a finer 220-400 grit sandpaper for polished edges.
  • Wipe away all dust when done sanding.

Step 8: Clean and Seal the Countertop

As a final step, thoroughly clean your countertop and seal the exposed cut edges:

  • Use soapy water to wash off all dust and debris from the project.
  • Apply color-matched caulk around the opening to seal it. Let dry completely.
  • Seal all sanded edges with a quartz sealer to prevent damage from moisture.
  • Allow sealer to cure fully before using the sink or cooktop.

And that’s it – you now have a professionally enlarged opening cut into your quartz countertop! Take your time with each step and ensure you have the proper tools. With care and patience, you can definitely take on this DIY quartz cutting project.

FAQs About Cutting Openings in Quartz Countertops

Can I cut an opening in quartz myself or do I need a professional?

With the right tools, cutting an opening in quartz is definitely a DIY-friendly project. The steps outlined above allow a careful DIYer to achieve professional looking results. However, for very complex cuts or if you prefer not to do it yourself, hire a fabricator.

What blade should be used to cut quartz countertops?

You’ll need a diamond-grit blade specifically designed for cutting stone and quartz. Diamond blades last longer than standard blades and provide smooth, clean cuts in quartz. Look for 4-inch angle grinder diamond blades.

How deep can I cut into my quartz countertop in one pass?

Don’t try to cut through the full 2-3 cm thickness of quartz in one pass. Cut incrementally in passes of 1/4 to 1/2 inch deep to avoid cracking the slab. Multiple light passes creates the opening safely.

Can I cut quartz countertops with a circular saw or table saw?

It’s best to use an angle grinder and rotary tool like a Dremel. The fine diamond blades and Dremel bits allow more control and reduce cracking. Don’t try cutting quartz with regular saws.

What’s the best way to get clean lines when cutting quartz?

Always measure and mark your outline very precisely. Tape can help guide your cuts. Cut relief lines first before the outline. Use the Dremel with a quartz bit to fine tune outlines. Take your time and don’t rush the blade.

How can I smooth the edges after making cuts?

Use 100, 220, and 400 grit sandpaper to polish and smooth the cut edges of the opening. Apply light pressure and gradually work up to finer grit. Finish by wiping away dust and sealing the edges to prevent moisture damage.


Enlarging an existing opening in your quartz countertop may seem tricky, but with careful planning and the right techniques you can achieve professional-looking results. Always use specialty quartz-cutting blades, cut relief lines first, make multiple shallow passes, check fit precisely, sand for smooth edges, and properly finish and seal the cutout area. With some time and patience, you can save money by safely DIYing this type of quartz countertop modification. Just remember to put safety first throughout the project.