How to Enlarge a Sink Cutout

Place the template piece that came with the new sink over the old cutout. If you don't have a template piece, flip the new sink upside-down and place it on the counter over the sink cutout.

Position the template or sink so it sits at least 1.5 inches from the counter’s backsplash or from the wall behind the counter, as well as the counter’s front edge. This keeps the sink’s cutout from cutting into the structure or frame of the sink cabinet and weakening it.

Trace around the perimeter of the sink or template with a marker, holding the marker vertically during the tracing process. Remove the template or sink from the counter and ensure that the outline you traced is complete. If you traced around the sink, draw a second line that sits 3/8 inch inside the tracing you made, so the sink’s lip sits on the counter.

Cut along the inside line you drew on the counter using a saber saw. Spread caulk on the bottom of the sink’s lip, then insert the sink into the enlarged cutout.