Measure the open floor where the island will go, counter to counter, both ways. You get the biggest island that fits with room to cook and walk around it, and how many stools it seats.
Island to plan
8′ × 3′ 3″seats 4 · a 42″ aisle to cook in, 44″ behind the stools
Quick answer: a kitchen island should leave a 42″ aisle on every working side (48″ if two people cook) and about 36″ at the ends. An island with seating is about 39″ deep (a 24″ cabinet plus a 15″ overhang for knees), with 24″ of counter per stool and 44″ behind the stools. The smallest useful island is about 4′ × 2′. In a space 14′ × 11′ between the counters, that is an island about 8′ × 3′ 3″ that seats four.
How to use the kitchen island calculator
- Measure the open floor where the island will go, both ways: from the counter fronts (or a wall, or the table) on one side to the ones on the other.
- Pick who cooks. Two people working at once need wider aisles.
- Choose seating along one side, or none. The answer is the biggest island that keeps every clearance, drawn to scale. Copy link keeps it.
The clearances that decide the size
The numbers come from the NKBA Kitchen Planning Guidelines, the standard kitchen designers work to.
- Work aisles: 42″ for one cook, 48″ for two or more. Enough to open a dishwasher or an oven door and still stand in front of it.
- Walkways: 36″. At the ends of the island, where people pass rather than work.
- Behind stools: 44″. From the counter edge to the next thing, so someone can walk past a person sitting.
- Seats: 24″ of counter each, with a 15″ overhang for knees at counter height. See the stool height calculator for the stools themselves.
Kitchen island size chart
The island the calculator plans for common spaces, one cook:
| Open space | With stools | Stools | Without seating |
|---|---|---|---|
| 12′ × 9′ | 6′ × 2′, no room for stools | 0 | 6′ × 2′ |
| 14′ × 10′ | 8′ × 3′, no room for stools | 0 | 8′ × 3′ |
| 14′ × 11′ | 8′ × 3′ 3″ | 4 | 8′ × 3′ 6″ |
| 16′ × 12′ | 10′ × 3′ 3″ | 5 | 10′ × 3′ 6″ |
| 18′ × 13′ | 12′ × 3′ 3″ | 6 | 12′ × 3′ 6″ |
Islands longer than about 10′ usually need a seam in the countertop: most slabs are not that long.
Three worked examples
A family kitchen, 14′ × 11′ of open floor. A 42″ work aisle and 44″ behind the stools leave room for an island 8′ long and 3′ 3″ deep that seats 4.
The same kitchen, two cooks. With 48″ aisles, a seating island no longer fits across: plan it 8′ × 3′ without stools, or put the stools at one end.
A small kitchen, 12′ × 9′. Only a working island fits: 6′ × 2′, no stools. A peninsula off a counter is the other way to get seating here.
Common kitchen island mistakes
- Too big for the room. An island that squeezes the aisles below 42″ turns the kitchen into a corridor. Size the aisles first, then the island.
- Stools with no overhang. Without 15″ of knee space, people sit sideways. Plan the overhang into the depth.
- Seating in the work path. Stools on the cooking side put guests between the cook and the stove. Seat them on the far side.
- Measuring the room, not the floor. Measure from counter front to counter front: the cabinets take 24″ or more from every wall they stand on.
Planning the layout? Draw the kitchen with its island to scale in the free 2D room planner, and pick stools with the stool height calculator.
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Kitchen island size questions
How big should a kitchen island be?
As big as the room allows while keeping a 42″ aisle on each working side (48″ for two cooks) and about 36″ at the ends. The smallest useful island is about 4′ × 2′; with seating it needs to be about 39″ deep.
What are standard kitchen island dimensions?
There is no single standard size: islands are sized to the kitchen. Most are 36″ tall (counter height), 24–42″ deep, and 4′–10′ long. An island with stools is usually about 39″ deep: a 24″ cabinet plus a 15″ overhang.
How much clearance do you need around a kitchen island?
At least 42″ on each side where one person cooks, 48″ where two do, and 36″ where people only walk past. Behind stools, leave 44″ so someone can walk past a person sitting.
What size kitchen island for 4 stools?
About 8′ (96″) long: 24″ of counter per stool. It also needs the 15″ overhang for knees, so about 39″ deep, and 44″ free behind the stools.
How deep should a kitchen island with seating be?
About 39″: a standard 24″ base cabinet plus a 15″ overhang, the knee space for counter-height stools. A bar-height overhang can be 12″, a table-height one needs 18″.
Can a small kitchen have an island?
Only if the open floor is about 10′ × 9′ or more: 4′ × 2′ of island plus the aisles around it. In a smaller kitchen, a peninsula off a counter or a rolling cart gives the same extra surface.