Installing an undermount sink can add a touch of elegance and modern style to your kitchen. Unlike a traditional top-mount sink that rests on top of the counter, an undermount sink is installed beneath the countertop creating a seamless look.

When it comes to installing an undermount sink, one of the key steps is properly placing the holes for the faucet and other accessories like a soap dispenser. Proper planning and precise measurement is crucial to ensure the accessories fit and function properly. In this guide, we’ll walk you through the process of determining the right location for holes when installing an undermount sink.

Planning the Layout

The first step is to plan out the layout of your sink area and decide where you want to place the faucet, soap dispenser, filtered water tap, or other accessories. It’s important to measure the actual sink basin and countertop first to understand the parameters you are working with.

Consider how the accessories will be used and create a practical layout. For example, you’ll want the faucet placed near the center of the sink basin within comfortable reach. The soap dispenser is best placed to the side of the faucet towards the user.

Make sure to check the dimensions of the specific faucet and accessories you’ll be installing to ensure proper clearance. Leave at least 1-2 inches between accessories to prevent crowded spacing.

Marking the Locations

Once you’ve determined the optimal layout, the next step is marking the exact hole locations. Place the actual sink upside down on top of the countertop to use as a guide. Mark the center point of each hole location with a pencil.

The key measurements needed are:

  • Distance from the sink edge to the center of each hole
  • Distance between each set of holes (faucet vs soap dispenser for example)
  • Distance from the backsplash to the first set of holes

These measurements will allow you to transfer the marks to the underside of the countertop when you go to drill the holes. Be as precise as possible for the best results.

Drilling the Holes

With the hole locations marked on the countertop underside, you can move on to carefully drilling the holes. Use a hole saw bit sized specifically for your faucet and accessories. Check manufacturer instructions for the exact hole size needed.

Drill slowly through the countertop material – whether solid surface, quartz, granite, or another material – keeping the hole saw steady and straight. Don’t force the drilling too aggressively to avoid cracking the countertop around the hole edges.

For faucet holes, drill a smaller starter hole through the countertop first before using the full sized hole saw. This prevents tear out damage on the underside hole edge.

Testing the Fit

Once the holes are drilled, test fit your faucet and accessories before permanently attaching anything. Carefully set the sink in place and insert the faucet shank and other accessories through the holes. This will confirm proper hole alignment and size before moving to the next steps of attaching the sink and accessories.

Minor adjustments can be made by enlarging holes slightly with a file if needed to accommodate any fittings. Taking the time to test first helps avoid headaches down the road.

Finishing Touches

With the holes drilled and a perfect fit confirmed, you’re ready to permanently install the sink, faucet, and accessories. Follow manufacturer instructions for securing each component properly.

Use silicone adhesive to seal around the sink edges and any accessory holes to prevent leaks and moisture damage.

Finally, admire your work and enjoy your stylish new undermount sink setup! Proper planning and precision at the hole drilling stage ensures everything fits beautifully.

FAQs about Undermount Sink Hole Placement

Where should the faucet hole be positioned on an undermount sink?

The faucet hole should be positioned roughly in the center of the sink basin, about 1-2 inches back from the front edge. This allows comfortable clearance under the faucet for handwashing and other tasks.

How far apart should the faucet holes be?

For a widespread faucet, the holes should be spaced 6-16 inches apart depending on the specific faucet model. Closer together drilling is required for single-handle faucets. Always check manufacturer specs for exact hole placement.

What is the standard size for an undermount sink faucet hole?

The most common faucet hole size is 1-3/8 inches for a standard residential bathroom or kitchen faucet installation. However, some faucet models may require 1-1/2 or 1-5/8 inch holes, so verify specifications.

Where should the soap dispenser hole be positioned?

The soap dispenser hole should be placed to the side of the faucet hole, closest to the user and within easy reach. Allow at least 1-2 inches of clearance from the faucet.

How do I avoid cracking the countertop when drilling faucet holes?

Work slowly with steady, even pressure when drilling to avoid cracking. Start with a smaller pilot hole before moving up to the full size hole saw. Place wood underneath for support and use tape around the hole location to prevent tear out.

Should I test fit the sink before permanently installing?

Yes, always do a test fit by temporarily setting the sink in place and inserting the faucet and accessories into the drilled holes before permanent attachment. This lets you confirm proper hole alignment and size.


Installing a stylish undermount sink provides a clean, contemporary look for your kitchen or bath. Paying attention to small but important details like proper faucet and accessory hole placement ensures everything functions correctly and looks seamless. Now that you know how to properly mark and drill holes for your sink accessories, you can install your sink with confidence. Just remember to double check measurements, drill carefully, and test fit before permanently attaching anything. With the right information and a precise approach, you can handle this project like a pro.