Cut a Countertop For a Sink

black two-sided kitchen sink
What You'll Need
Circular saw
Pencil or wax crayon
Tape measure (possible)

Cutting a countertop sink is a popular home renovation that doesn’t require a professional. It does take some skill and know how, but with the right tools and preparation, it’s a project that most people can complete in less than a day. Here’s what you need to know.

Step 1 - Measure

The first thing you need to do is to measure the countertop for the new sink. You can do this by simply placing the sink on top of the countertop with the bowl facing down and tracing along the bottom of the sink with your pencil or crayon. This will give you a working guide as to where you need to place the actual cut.

Once you have your outline you will need to create another mark on the inside of this. Make the mark 3/16 of an inch inside the original tracing. These interior marks are actually where you are going to cut. Sinks have a groove on the base that is about 3/16 of an inch, so this is why the cut mark will differ slightly.

Step 2 - Start the Cut

assortment of drill bits

Using your drill with an appropriate drill bit, start a cut on the countertop. This cut needs to be large enough that the circular saw will fit in to the hole you created. Most often you will need to start by drilling a small hole and then changing to a bigger drill bit to enlarge it. Depending on the material of the countertop, the bit you need can vary. If you’re unsure which bit will be best with your countertop an expert at your local hardware store can point you in the right direction.

Step 3 - Finish Cutting

Now use your circular saw to finish cutting along your cut line. Don’t cut it completely out though. Before you get the cut all the way around you will want to attach a piece of wood underneath the countertop using your drill. This will prevent the piece you are cutting from smashing under the counter. Once you have your wood attached you can finish the cut until it’s completely cut out.

After the final cut, remove the wood and lower the piece down so you don’t shatter it or cause damage to the underside of your cabinet.

Step 4 - Apply Sealant

Now that you have a hole ready for a sink, you will want to apply sealant around the cut. This should be done right before you are going to place the sink. Once this starts to dry it will be worthless. You also need to use care when you place the sink to avoid smudging it.

Additional Tips and Tricks

To avoid scratching the sides of the countertop, you can apply a heavy masking tape to the cuts before you place the sink.

Have someone with you as you place the sink down in the newly cut hole. The sinks are usually pretty heavy and awkward to work with, and this will help prevent damage to your sink, countertop, and even yourself.