Short definition
A sink cutout is the opening in a counter that a sink drops into (drop-in / self-rimming) or hangs below (undermount). For drop-in sinks, the cutout is sized so the rim overhangs the cut by roughly half an inch on all sides — forgiving on tolerance. For undermount sinks, the cutout edge is the visible bowl rim, so it has to be cut precisely.
What it is
Most new sinks ship with a paper template sized to the bowl. The template is taped to the counter, the rim outline is traced, and a second cut line is marked half an inch inside the trace. Pilot holes (3/8 to 1/2 inch) are drilled at the corners of the cut line, and a jigsaw or saber saw runs the cut. For drop-in sinks, the bowl rim then covers the half-inch reveal completely, hiding any imperfection.
For undermount sinks, the cut line is the trace itself — no offset — because the cut edge becomes the visible bowl rim. The cutout is smaller than a drop-in cutout for the same bowl, and the tolerance is much tighter (template-precise). On stone or quartz counters, the cutout is made by a stone shop with a wet diamond saw, not by jigsaw.
Trade tip from the carpentry side: score the laminate along the cut line with a sharp utility knife before sawing, and cut from below where possible. Both tricks prevent chip-out on the visible face.
Why it matters to a homeowner
The cutout is the highest-stakes step in a DIY sink install. Cut it too small and the sink won’t drop in; you can shave a side or two with a flush-cut router or careful jigsaw work. Cut it too large — by half an inch or more — and the rim won’t cover the cut. At that point you’re either patching the counter (plywood plus new laminate) or upsizing the sink to one with a wider flange. Neither is a quick fix.
Two practical anchors:
Going from drop-in to undermount almost always means a new counter. The undermount cutout for the same bowl is smaller than the drop-in cutout, and you can’t shrink an existing hole.
Stone counters are not a DIY cut. A standard saber saw will crack the slab. If your sink swap requires changing the cutout shape on stone or quartz, budget for a stone shop visit ($300 to $800 typical) or a new counter.
Common failure modes
- Cutout too large — over-cut by half an inch or more; rim won’t cover. Patch the counter or upsize the sink.
- Cutout too small — sink won’t drop in. Trim each side carefully with a flush-cut router or fine-tooth jigsaw blade.
- Chip-out on laminate — finish chips when cutting from the top side. Score with a utility knife first, or cut from underneath.
- Cutout misaligned with the cabinet centerline — sink and cabinet don’t line up; visually noticeable and hard to disguise. Plan template placement before cutting.
- Cracked stone — jigsaw on a stone counter cracks the slab. Stone is wet-diamond-saw work only.
Common variants and what a sink cutout is not
- Drop-in cutout vs. undermount cutout. Drop-in is hidden by the rim; tolerance is loose. Undermount is the visible bowl rim; tolerance is tight.
- Sink cutout vs. sink template. The template is the paper guide that ships with the sink; the cutout is the resulting hole.
- Saber-saw cutout vs. router cutout. Jigsaw and saber saw are the DIY tools. Pros may use a router with a template guide for cleaner cuts on solid-surface or hardwood counters.
- Sink cutout vs. faucet hole. Faucet holes are the small (1⅜-inch standard) holes drilled in the back deck of a sink or counter. Different cut, different tool (hole saw or punch).