It is recommended that your base cabinet be 3 inches larger than the size of the farmhouse sink you are considering to install.
TIP: Standard cabinet sizes are in 3” increments. I.E.: 27”, 30”, 33”, 36”, etc. In general your sink should be at least 2-3” smaller than your cabinet size.
To determine the maximum sink size for your base cabinet, measure the interior of your cabinet and subtract two to three inches from each dimension. A 36″ base cabinet can handle a 33″ sink at most; a 30″ cabinet should be fitted with a sink no larger than 27″ wide.
When selecting, or designing, a base cabinet for your new farmhouse sink, it is important that the size of the base cabinet is correct. Your base cabinet should measure 3" longer in length than the sink you are installing. For example, if you have a base cabinet that measures 36" wide it will support a 33" sink.
A typical 33 x 22-inch sink will fill a 36-inch base cabinet. If you're replacing a sink, make sure it fits the existing cutout. If the cabinet allows, you may be able to install a larger sink by expanding the cutout.
The standard size for a kitchen sink can vary, but a typical size for a single-bowl sink is around 30 to 33 inches in width and 20 to 22 inches in depth. Double-bowl sinks can range from 30 to 48 inches in width, depending on the bowl size and configuration.
The recommended size for a 36" base cabinet is a 33" farmhouse sink or smaller. It is recommended that your base cabinet be 3 inches larger than the size of the farmhouse sink you are considering to install.
A 33" cabinet will only fit a 30" sink.
To put in a farm sink, you have to cut out the existing cabinet front, top, and even back, depending on how much space you need. Since these types of sinks have their aprons exposed, it's important for you to follow the template that comes with your farm sink.
To make space for the extra-large sink, you'll need an 'apron-skirt' cabinet design. A farmhouse sink can't fit into the usual drop-in sink space and extends over the top quarter of the lower cabinet. This requires a full re-design of the cabinet and countertop where your farmhouse sink is installed.
Which means you CAN fit some "thirty" inch sinks in a 30" kitchen sink base cabinet. However, definitely take a look at each sink's specifications to make sure it will fit in your cabinet. A sink with a basin dimension that is close or the same as your inside cabinet dimension will be a tight fit.
If there isn't enough width available in the cabinet, you won't be able to go for the bigger sink, even if there is room on the counter. Also, remember that you are going to have to create a larger hole in the counter to suit the new sink.
Kitchen Cabinet Kings
General rule of thumb is actual sink should be 3" in actual width less than the sink base for smooth fit. However if you notch the sides of the cabinet, you should be able to get something as tight as 1.5 less than cabinet to fit.
Standard sink base cabinet widths
Standard sink base cabinet dimensions range from 30 to 42 inches wide. 30 inches is the standard single basin sink base width. 33 inches is the typical double-basin, offset sink cabinet size.
The standard base cabinet widths are 12, 15, 18, 21, 24, 26.25, 27, 30, 33, 26, 39 and 42-inches. Filler cabinets are available in 6 and 9-inch widths.
A 36" sink will fit into a 36" cabinet easily if you strap it in place. Manufacturer's allow for chubby plumber fingers to access clips to tighten.
A farmhouse sink needs supports attached to the inside of the cabinet because it's heavy. Some can weigh over 300 pounds when filled with water. The top of the sink needs to be even with the cabinets so the counter will sit correctly.
We normally go ⅜ inch inside the sink for the overhang, but this can be flexed for the look you desire.
Kohler makes farmhouse sinks with smaller aprons to keep the same aesthetic in a more manageable size for some cabinets. In most new homes the kitchen sink is approximately 30 inches in length, which is a standard size for a farmhouse sink. The other standard sizes are 24, 33, and 36 inches.
A good place to start when looking for the right size is with the most popular sizes for farmhouse sinks, small, medium, and large. Or the most common, either a 30″ or 33″ single bowl.
Both types of sinks are huge, large, and quite deep. However, the apron sink's front area is exposed and visible- which is why they are called apron sinks. These are versatile and modern houses prefer apron sinks. But on the other side, farmhouse sinks look adjacent as well as covered by the kitchen cabinets.
Unlike regular “drop-in” sinks, which are lowered into a countertop cavity, farmhouse sinks are installed beneath the counter and rest on top of a base cabinet. They, therefore, require a special cabinet configuration, but it's entirely possible to convert an existing drop-in setup to accommodate a farmhouse sink.
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.
The most common countertop overhang is 1.5″. We wanted our sink to go about 1/2″ past the countertop, so we positioned our sink so that it would go 2″ past the cabinet face frame/front of the cabinet.