Measure the sink cutout length from the left inside edge to the right inside edge
Measure the sink cutout width from the front inside edge to the back inside edge
Measure the countertop opening at the widest points
Measure the sink bowl depth from the rim to the bottom of the basin
Measure the overall sink length from outer edge to outer edge
Measure the overall sink width from outer edge to outer edge
Measure the rim or lip width around the sink
Measure the cabinet width under the sink
Measure the distance from the back wall to the front edge of the countertop
Measure faucet hole spacing if the sink has pre-drilled holes
Measure drain opening diameter
Measure the distance from the sink center to the drain opening
Measure the distance from the sink edge to any mounting holes or clips
Measure the apron height and width for apron-front sinks
Measure the sink’s corner radius if replacing a rounded-corner sink
Measure the thickness of the countertop where the sink will be installed