How to Determine the Size of an Undermount Sink

Measure your counter top space using a tape measure. Take a measurement for the counter top length and width. Write the measurements down with a paper and pencil.

Divide the length of the counter top by .25, and write down the result. Most kitchens require a sink that is about a quarter of the length of the counter top where you perform most of your cooking. Add up to two inches of length to account for the lack of a rim on undermount sinks. The lack of a rim gives more counter space for cooking and cleaning up.

Consider your particular kitchen cleaning and cooking needs. For instance, if you cook a lot, choose a sink that is closer to the result you got in step 2. If not, you can select a sink that is slightly smaller than the average size of 32 inches long and 22 inches wide.

Consider how often you wash dishes and if you wash dishes in the sink. Consider a double sink instead of a single sink bowl. This will affect the size of your undermount sink. Double sinks typically feature two similarly sized bowls with an overall length of around 36 inches.

Consider the width of your faucet base; if it mounts behind the undermount sink, there must be enough room. While most undermount sinks are 22 inches wide, some larger sinks are available. Only choose a wider sink if you have a counter top wider than the average, which is 24 inches.