If you need to replace a broken sink or just want add a new style to your kitchen or bathroom, measuring will be necessary. Regardless of the reason, measuring for a new sink isn't difficult and doesn't require any special tools. However, you'll need to consider the style of sink you want to install when you take measurements. Self-rimming sinks feature a lip that runs around the edge of the sink and on top of the counter. Under mount sinks sit below the surface of the counter. Pedestal and wall mount sinks feature faucets that attach directly to the sink bowl, not the counter.
Measure the depth of the cabinet opening with a tape measure, running the tape measure from the back to the front of the opening.
Measure the height of the sink by placing the tape measure or a ruler at the bottom of the sink next to the drain. Place a straightedge across the width of the sink to find the exact depth of the sink.
Measure the width of the sink by stretching the tape measure from one side to the other of the sink's edge.
Ensure that your cabinet will accommodate the new sink. Add 1 ¼ inches to the total depth (see measurement in Step 1) of the sink size to accommodate for ½ inch support at the front of the sink, and at least ¾ inch at the back of the sink to accommodate a faucet that you can easily clean behind.
Determine the sink's approximate cubic volume by multiplying the depth, height and width in inches. The numbers will be slightly off for rounded bottom sinks, such as those used in a bathroom.