How to Measure Undermount Kitchen Sink

Whether installing a new kitchen sink or simply revamping your kitchen, you can never go wrong with an undermount kitchen sink.

These sinks have no lips or crevices to catch dirt. You just wipe spills directly into the sink without getting under the rim.

In addition to easing cleanup, undermount sinks enhance the style of any kitchen. They provide a sophisticated, streamlined look to your kitchen’s décor.

However, unlike drop-in sinks, undermount sinks require a lot of support. That’s why if you are looking forward to installing an undermount in your kitchen, you need to get the right measurements.

The amount of cabinet and counter space you’ll need for your undermount sink depends on how you measure the sink.

In this post, post we help you figure out how to measure an undermount kitchen sink for easy setup.

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Taking the Measurements

Measuring an undermount sink is an easy task and should take only a couple of minutes.

To describe the sink completely, you’ll need to get the following dimensions.

  • Length
  • Width
  • Height
  • Sink lip
  • Cabinet opening width
  • Length and width of countertop hole

Materials You’ll Require

To get the right measurements, you’ll require the following tools:

  • Measuring tape or ruler
  • Leveling tool
  • Pencil/pen and paper
  • Step 1: Measure the Length

The length of an undermount sink is its longest edge.

To get the right length dimensions, place the measuring tape at the farthest edge of the sink and extend it to the other end.

Ensure that the edges you are measuring are those farthest away from one another. Write the figures down so that you won’t forget them.

  • Step 2: Measure the Width

The width is the shortest edge of your sink.

To get the right width dimensions, extend your measuring tape across the sink from the back outer edge (the edge nearest to the faucet) to the front outer edge.

Write down the measurements.

  • Step 3: Measure the Height

Getting the right measurements for an undermount sink’s depth/height will help you know how much space it’ll occupy vertically.

Stretch your tape measure from the top to the underside bottom of the sink. To get the correct figures, ensure that the tape measure runs straight. Note down the measurement.

  • Step 4: Measure the Lip/Rim

The lip of the sink is the space between the edge of the undermount sink and the edge of the countertop. Usually, it isn’t more than 1-inch in length.

All sides should have equal measurements. However, for variations less than 1/8-inch, the measurement is insignificant.

  • Step 5: Measure the Countertop Hole

Now that you have the list of your sink dimensions, you need to slice a hole on the countertop where you’ll insert the fixture.

To get the right dimensions, add the sink rim’s measurements from the right and left sides and subtract the answer from the length measurement.

For the width, use the same concept. Add the sink lip measurements on the back and front sides, and then subtract the value from the width measurements you recorded earlier.

And since undermount sinks don’t feature a lip that rests on the countertop like the drop-ins, the interior measurement should match the cutout size.

  • Step 6: Measure the Cabinet Opening

If you have a cabinet under your countertop, measure its width before purchasing a new sink. Crawl under the counter and place the tape measure from the top left corner of the cabinet to the top right corner.

Write down the measurement.

Ensure that you get a sink whose width is smaller than that of the cabinet. Otherwise, it won’t be a good fit.

Measuring an Undermount Kitchen Sink for Replacement

Over time, your kitchen sinks become worn out, especially because of heavy use. If you want to replace the old sink with a new one, remove it and take the measurements.

Follow the steps listed above to measure the sink.

After getting the right measurements, you can purchase an identical sink or buy a different model with similar measurements.


Getting the right dimensions for your undermount sink will help you install the fixture with ease. In fact, you won’t have to get a professional to help you complete the task for you.

We hope that the guide helps you sort out your confusion. All the best!

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