Kitchen sink size calculator
As a rule of thumb, a kitchen sink should be at least 3 inches narrower than its base cabinet: up to 27 inches in a 30 inch base, 30 inches in a 33 inch base and 33 inches in a 36 inch base. Undermount models often require a 33 or 36 inch base, so check the spec sheet.
Updated · By the Interior Redesign AI editorial team · Sources cited on the page
Hangs under a stone or solid-surface top. Models often need 33-36 in bases; check the spec sheet.
Rule of thumb: the sink's outside width should be at least 3 in less than the base cabinet's outside width. Every sink's spec sheet lists its own minimum base cabinet, and that number wins.
Largest sink for this base
30 in wide
Common sizes that fit: 30 in, 28 in, 27 in, 25 in.
| Base cabinet | 33 in |
|---|---|
| Max sink outside width | 30 in |
| Double bowl practical? | Yes (30 in or wider) |
| Landing space either side (NKBA) | 24 in + 18 in |
| Counter run for sink + landing | 72 in |
| Dishwasher | Within 36 in of the sink edge |
Leave 21 in of standing space between the dishwasher edge and any counter or cabinet at a right angle to it (NKBA Guideline 13).
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Key numbers
- Rule of thumb
- Sink outside width = base width − 3 in or less
- Most common sink base
- 33 in or 36 in
- Landing space
- 24 in on one side of the sink, 18 in on the other (NKBA Guideline 11)
- Prep area
- 36 in wide × 24 in deep next to a sink (Guideline 12)
- Dishwasher
- Within 36 in of the sink edge, with 21 in of standing space (Guideline 13)
- Spec sheet
- Each model lists a minimum base cabinet; it overrides the rule of thumb
Worked example
An undermount sink in a 33 inch base
A standard 33 in sink base cabinet with a quartz top and an undermount sink.
- Max sink width: 33 − 3 = 30 in.
- Common sizes that fit: 30, 28, 27, 25 in.
- Counter run for a 30 in sink plus NKBA landing (24 + 18 in): 72 in.
A 33 in base takes a sink up to 30 in wide; check that the model's spec sheet allows a 33 in base for undermount.
How we calculate
We take your sink base's outside width and subtract 3 inches. That leaves room for the cabinet sides and the mounting hardware, and it is the usual rule of thumb. We then list the common sink widths sold in the US that fit inside that number.
The rule of thumb is a starting point, not a guarantee. Manufacturers such as Kohler print a minimum base cabinet width on each sink's specification sheet, and undermount sinks often need a wider base than the same sink mounted from the top. Apron-front sinks need an apron sink base sized to the sink.
The landing space and dishwasher numbers come from the NKBA Kitchen Planning Guidelines. They are planning guidelines, not code.
Estimates, sources
Planning estimates and published guidelines, not quotes, designs or code rulings. Local prices, your home and your jurisdiction's adopted code decide the real answer: get local bids and check with your inspector.
- Kitchen sink specification sheet (minimum base cabinet) (Kohler, 2024): each model lists a minimum base cabinet width, often larger for undermount than for top-mount
- Kitchen Planning Guidelines with Access Standards (National Kitchen & Bath Association (NKBA), 2015): work triangle 26 ft max, legs 4-9 ft; aisles 42 in (one cook) / 48 in (two); walkways 36 in; seating clearance 32/36/44 in; knee space 24 in wide; landing areas; 150 cfm ventilation; storage frontage
- Cabinet specifications catalog (standard sizes) (Jarlin Cabinetry, 2026): base and wall cabinets in 3 in width steps (9-48 in); base 24 in deep, 34.5 in high; wall 12 in deep
Sink size by base cabinet
Use this chart to shortlist sinks, then confirm the model's minimum base cabinet on its specification sheet.
| Base cabinet | Max sink width | Typical choice |
|---|---|---|
| 24 in | 21 in | Single bowl |
| 27 in | 24 in | Single bowl |
| 30 in | 27 in | Single bowl |
| 33 in | 30 in | Single or double bowl |
| 36 in | 33 in | Single or double bowl |
| 42 in | 39 in | Single or double bowl |
| 48 in | 45 in | Single or double bowl |
Undermount, top-mount or apron-front?
Undermount sinks look clean and make wiping crumbs easy, but they need a solid-surface or stone top and often a wider base. Top-mount (drop-in) sinks fit the tightest base for their size and work with laminate. Apron-front sinks show their front and need a matching sink base or a modified cabinet.
How to use this tool
Measure the sink base
Outside width of the cabinet, or pick 24 to 48 in.
Pick the mount
Undermount, top-mount or apron-front.
Shortlist sinks
See the max width and the common sizes that fit.
Check the spec sheet
Confirm the model's minimum base cabinet before ordering.
Questions
What size sink fits a 33 inch base cabinet?
Up to about 30 inches wide by the 3 inch rule of thumb. Many undermount models list 33 inches as their minimum base, so check the specific sink's spec sheet.
What size sink fits a 30 inch base cabinet?
Up to about 27 inches. Some top-mount sinks are rated for a 30 inch base while the same size undermount needs 33 inches.
What size sink fits a 36 inch base?
Up to about 33 inches, which covers most large single bowls and double bowls. Some apron-front sinks need a 36 inch base.
How much counter do you need beside the sink?
NKBA recommends a 24 inch landing area on one side and 18 inches on the other, plus a 36 inch wide prep area next to a sink.
How far can the dishwasher be from the sink?
NKBA recommends the nearest edge of the dishwasher within 36 inches of the sink edge, with 21 inches of standing space beside it.
Is single or double bowl better?
Double bowls are practical from about a 33 inch base up. In smaller bases, one large bowl usually works better for big pans.
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