Measure the opening width under your existing sink (or where the new one will be installed) from left to right. This measurement is your cabinet size. Then, allow at least 2-3 inches on both sides for mounting hardware. For example, a 36" cabinet can accomodate a 30-32" sink.
What is a standard size undermount sink?
The most common sizes for a kitchen sink are 30" or 33", however a standard size could measure anywhere between 24" and 36" in length. The bulk of what you find while shopping will fall within this size range. Generally, sinks up to 30" will contain one large single bowl.
How do I measure for undermount sink cabinets?
If you have an undermount sink, measure from the edge of the counter opening. Measure the length of your sink by placing the edge of your tape measure on the left edge of the sink and stretching it across to the right edge. Write down the length.
What size undermount sink fits in a 36 inch cabinet?
A 30-inch wide or a 36-inch wide cabinet are most common. The height of the cabinet can be customized, but 36 inches is average. A typical 33-by-22-inch sink will fill a 36-inch base cabinet.