Requirements for a kitchen sink base cabinet include enough room to accommodate the sink. Common sink sizes are 30, 33 and 36 inches side to side; some measure at 42 inches, but not often.
Sink width from front to back, is typically 22 inches. Cabinet depth, from the wall side to the front of the cabinet, is standardized at 24 inches.
The actual countertop cutout for the sink is typically 1 to 1 1/4 inch smaller than total overall width and length of the sink. The sink must also fit between the two vertical side jambs of the cabinet.
Cabinet Size Variations
Kitchen cabinets, sink cabinets included are often slightly smaller in height than the finish size to account for the countertop's height. For example, installing a countertop on a cabinet typically adds 3/4-inch or more to the height and 1 inch to the width, unless the cabinet and countertop butts the wall.
Cabinet manufacturers allow for this, and the actual sink cabinet height without the top typically measures 35 1/4 to 35 1/2 inches unless you ask for custom heights. Due to the addition of fascia and overhanging countertop along the front, cabinets with a countertop often measure 25 inches in depth or slightly more.
Some cabinetmakers allow for the countertop, and the cabinet will only measure 22 1/2 to 23 inches in depth before the countertop is added.
Sink Cabinet Characteristics
Sink cabinets appear different on the inside than other base cabinets. Sink cabinets have no back or drawers.
They are basically a hollow shell with two sides and a bottom shelf. Sink cabinets butt directly to the drywall, with a 3/4 by 3 1/2-inch pine rail horizontal across the back.
Hardboard backing -- typical on some cabinets -- is left off to accommodate plumbing. Drawers are left out make room for the sink and plumbing.
Sink cabinets typically have two doors on the front and sometimes fake drawer fronts attached to the face frame to match existing drawers on other cabinets.
Toe-Kicks and Aprons
Base cabinets have a toe-kick, which is a 3 by 3 1/2-inch recess at the bottom. The toe-kick provides room for your toes when you're standing at the sink.
Face frame widths are often standardized and typically measure 3/4 by 3 inches in width for vertical pieces or stiles, and 2 inches in width for horizontal members or rails. The bottom rail is typically 1 1/4 to 1 1/2-inches wide.
Install a sinks after securing the base cabinets together and adding the countertop. Common sinks drop into the cabinet from the top.
Another type of sink, such as an apron or farmhouse sink, may require that the front, top rail of the cabinet be removed.