Standard kitchen cabinet dimensions, and why the numbers fit together
Kitchen cabinets come in a small set of sizes that almost every maker in North America agrees on: 34½" tall base cabinets, 24" deep, 12" deep wall cabinets hung so their undersides land at 54", and widths that step in 3" from 9" to 48". The list is easy to find. What is worth knowing is that the numbers follow from each other, that nothing in law or standard requires them, and that appliances are what hold them in place. Once you can see which number is load-bearing, you can tell which ones you are free to change. Inches first throughout, millimetres in brackets.
A base cabinet is 34½" (876 mm) from the floor to its top edge and 24" (610 mm) deep. Add a 1½" (38 mm) countertop and you get the 36" (914 mm) work surface everyone calls counter height. Leave 18" (457 mm) of backsplash above it and the wall cabinets start at 54" (1372 mm), where they are 12" (305 mm) deep. Widths run in 3" steps. Tall cabinets are 84, 90 or 96", which is 54 plus a 30, 36 or 42" wall cabinet, so the tops of a run line up.
The vertical stack, top to bottom
Read this table downwards and the kitchen assembles itself. Each number sits on the one below it, which is why changing any single one has consequences three rows away.
Dimension
Inches
mm
Note
Base cabinet, floor to top
34½"
876 mm
The carcass plus what it stands on.
of which carcass
30"
762 mm
The box itself. Ours sits on four adjustable legs.
of which toe kick
4½"
114 mm
Our figure. KCMA asks only for 3" tall and 2" deep as a minimum.
Countertop thickness
1½"
38 mm
Nominal. Stone, laminate and butcher block all land near it.
Work surface, finished
36"
914 mm
34½ + 1½. This is what people mean by counter height.
Toe kick setback
3"
76 mm
How far the kick panel is recessed so your toes go under.
Gap, counter to wall cabinets
18"
457 mm
The backsplash. 15–20" is all in use; 18" is the default.
Wall cabinet, underside from floor
54"
1372 mm
34½ + 1½ + 18. A consequence rather than a separate rule.
The arithmetic is the point. 34½ + 1½ + 18 = 54. Then 54 + 30 = 84, 54 + 36 = 90, 54 + 42 = 96, which are the three standard tall cabinet heights. A pantry and a run of wall cabinets finish on the same line without anything being trimmed, because someone chose the wall cabinet heights so they would. Nobody memorises seven numbers here. They memorise two, 34½ and 18, and the rest follows.
Where these numbers come from
Most size charts leave this part out, and it changes how you should treat the whole list.
No standard requires any of it. The industry standard people reach for is ANSI/KCMA A161.1, and it says of itself that it is "a performance and construction standard only… not intended to specify cabinet design". What it contains is tests: load a shelf, cycle a door 25,000 times, hang 600 lb off a wall cabinet for four minutes, drop a steel ball on a drawer bottom. It has plenty to say about whether a cabinet survives and nothing to say about whether it is 34½" tall.
Appliances hold the grid in place.A dishwasher and an under-counter oven are built to slide into an opening of about 34½". A range hood sits a fixed distance above the burners. Countertop material comes in standard depths that suit a 24" box. The grid persists because deviating from it costs you compatibility with things you did not manufacture, and that is a much stronger force than any rulebook.
So the numbers are conventions with teeth. You can change them, we will build to whatever you draw, and the only question is which downstream thing you are agreeing to give up. The guide to counter height for your height works through that trade in full.
Depth: three different answers, on purpose
Depth is where people expect one number and find several, because base and wall cabinets solve unrelated problems.
Cabinet
Inches
mm
Base cabinet
24"
610 mm
Tall cabinet / pantry
24"
610 mm
Wall cabinet
12"
305 mm
Wall cabinet, deep (over a hood)
15"
381 mm
Wall cabinet over a fridge
24"
610 mm
Bathroom vanity
21"
533 mm
A base cabinet is 24" deep because a countertop, a dishwasher and a person leaning over a worktop all want that number. A wall cabinet is half that because you have to stand under it: at 12" it clears your head and lets you see the back of the counter, and every extra inch of depth is an inch of work surface you can no longer look down at. Where nobody stands, over a fridge or over a hood, the depth goes back up. The full argument, including when a shallow base or a deep wall cabinet is the right call, is in the cabinet depth guide.
Width: the 3-inch ladder
Cabinet widths step in threes. Every maker's catalogue is built on the same ladder, and you plan a kitchen by choosing rungs that add up to your wall:
9"
229 mm
12"
305 mm
15"
381 mm
18"
457 mm
21"
533 mm
24"
610 mm
27"
686 mm
30"
762 mm
33"
838 mm
36"
914 mm
39"
991 mm
42"
1067 mm
45"
1143 mm
48"
1219 mm
Two consequences worth knowing before you plan a wall:
The leftover is a filler.Walls do not come in multiples of 3". Whatever is left at the end of a run, anything under 3", gets closed with a plain strip of matching board, scribed to the wall on site. It is normal, it is cheap, and it is how a stock kitchen fits a wall that measures 137¼".
24" is where doors double.Up to and including 24" a cabinet gets one door; wider than that, a pair. It is a practical limit rather than a rule, since one 30" door would be a heavy slab hanging off one edge and would need half the room to open. The hinge guide explains why width, not height, is what loads a hinge.
Our own cabinets are not restricted to the ladder, since the editor takes any width you type, to the millimetre. The ladder still matters, because a kitchen designed on it is one you can appliance-fit, quote and rework later without redrawing the whole run.
Wall cabinet heights
Wall cabinets come in a ladder of their own. Your ceiling and whatever sits underneath the cabinet decide which one you want:
Height
mm
Where it goes
12"
305 mm
Over a fridge, or a shallow band over a window
15"
381 mm
Over a fridge; short runs
18"
457 mm
Over a range hood or a fridge
24"
610 mm
Over a sink window; short ceilings
30"
762 mm
The workhorse. Tops out at 84" with the run
36"
914 mm
Taller ceilings; tops out at 90"
42"
1067 mm
Ceiling-height look; tops out at 96"
On a standard 8-foot ceiling, a 30" wall cabinet finishes at 84" and leaves a foot of soffit above it. A 42" one runs to 96" and meets the ceiling: no dust ledge, more storage, and a top shelf you will need a step stool to reach. Neither is more correct. They are different bargains with the same wall.
What is a decision rather than a standard
Some of the numbers above belong to the industry and some are ours. A size chart that presents every figure as immutable is quietly wrong, so here is which is which:
Frameless, not face-frame.Much of the US market builds a face-frame cabinet with a 1½" frame across the front. We build the European frameless box. The outside dimensions match; the openingdoes not, since a frameless 18" cabinet gives you a clear 425 mm where a face-frame one gives about 371 mm. See frameless vs face-frame.
A 4½" × 3" toe kick.The market norm, and comfortably above the 3" × 2" minimum in the standard, but still a choice. How a cabinet meets the floor covers what else lives down there.
A 6" drawer over a 24" door, and a 6/12/12" split on a three-drawer base. The most common arrangement rather than the only one, since 5/5/5/8" and 15/15" both exist and both work.
The 18" backsplash gap.Standard by convention; 15" and 20" are both in wide use, and the gap has its own guide because people want to change that number more than any other.
What breaks when you move a number
A map of the blast radius, since this is what the chart is for:
Lower the base cabinets and your dishwasher no longer fits under the counter. This is the most expensive change on the page, and the reason to make it at the legs rather than the carcass where you can.
Change the countertop thicknessand everything above it moves. A 3" slab eats an inch and a half of your backsplash or pushes the wall cabinets up.
Raise the wall cabinetsfor a taller backsplash and the top shelf leaves the reachable zone. Above about 54", every inch you gain in comfort at the counter is an inch you lose at the top of the cabinet.
Deepen the wall cabinetspast 12" and you will find them with your forehead at the sink. If you need the storage, the honest fix is a taller cabinet.
Abandon the 3" width ladder and nothing breaks, since this is the number with the least holding it in place. It costs you the ability to swap in a stock module later.
Start from the standard, then change what you need
Our kitchen modules are built on exactly the grid above: 34½-inch bases, 24 inches deep, wall cabinets hung at 54, widths in 3-inch steps. Open one, type a different number, and everything downstream rebuilds around it, from the fronts and the drilling to the parts list and the price. The standard is a starting point, not a cage.
Base cabinets are 34½ inches (876 mm) tall and 24 inches (610 mm) deep, which with a 1½ inch countertop gives a 36 inch (914 mm) work surface. Wall cabinets are 12 inches (305 mm) deep and are hung with their undersides 54 inches (1372 mm) off the floor, leaving an 18 inch backsplash gap. Wall cabinets come 12, 15, 18, 24, 30, 36 or 42 inches tall; tall cabinets and pantries are 84, 90 or 96 inches. Widths step in 3 inch increments from 9 to 48 inches.
How tall are kitchen base cabinets?
34½ inches (876 mm) from the floor to the top of the box, typically a 30 inch (762 mm) carcass standing on a 4½ inch (114 mm) toe kick or on adjustable legs set to that height. Adding a nominal 1½ inch countertop brings the finished work surface to 36 inches (914 mm). That 34½ inch figure matters more than it looks: dishwashers and under-counter ovens are built to slide into an opening of about that height, so it is the number that keeps a kitchen compatible with appliances you buy separately.
Is there an official standard for cabinet sizes?
No. The standard people cite, ANSI/KCMA A161.1, states plainly that it is a performance and construction standard only and is not intended to specify cabinet design. What it contains is tests: shelf loading, 25,000 door cycles, 600 lb hung from a wall cabinet, impact tests. The familiar 34½ and 24 inch figures are a market convention held in place by appliances and countertop materials rather than by any rule. Building codes touch a kitchen in a few places, such as the clearance above a cooktop, but they do not size cabinets either.
How deep are kitchen wall cabinets?
12 inches (305 mm) as standard, half the depth of a base cabinet, because you stand underneath a wall cabinet. At 12 inches it clears your head and still lets you see the back of the counter, and every additional inch of depth hides more of the work surface and gets closer to your forehead at the sink. Deeper wall cabinets exist where nobody stands under them: 15 inches over a range hood, and 24 inches over a refrigerator, matching the fridge's depth.
Why are cabinet widths in 3 inch increments?
Because you plan a kitchen by adding cabinets up to the length of a wall, and a coarse ladder of sizes from 9 to 48 inches turns that into a small arithmetic problem instead of a bespoke one. Real walls are not multiples of three, so whatever is left over gets closed with a filler strip of matching board, scribed to the wall on site. Cabinets up to 24 inches wide take a single door; wider than that, a pair. Custom widths are perfectly buildable, and ours take any dimension to the millimetre, but a kitchen laid out on the ladder is much easier to modify later.
Can I have taller or shorter cabinets than standard?
Yes, and it is often a good idea, but change the height at the base rather than the box where you can: adjustable legs and a taller or shorter toe kick move the whole cabinet without disturbing anything else. What resists change is appliances that fit under the counter, countertop and backsplash materials cut to standard heights, and resale expectations. A raised or lowered work surface for a specific person is one of the strongest arguments for a made-to-measure kitchen. Just make the decision knowing which appliance openings you are agreeing to give up.
How high should wall cabinets be hung above the counter?
18 inches (457 mm) is the default, which places their undersides 54 inches off the floor. That figure is what is left when you stack a 34½ inch base cabinet, a 1½ inch countertop and the gap, and it was chosen so that 54 plus a 30, 36 or 42 inch wall cabinet lands exactly on the standard 84, 90 and 96 inch tall-cabinet heights. Anywhere from 15 to 20 inches is in common use, and the trade-off is straightforward: a bigger gap gives you more room to work at the counter and a taller backsplash, and it moves the top shelf further out of reach.
What size are tall pantry cabinets?
84, 90 or 96 inches tall (2134, 2286 or 2438 mm) and 24 inches deep, the same depth as a base cabinet. Those three heights are not arbitrary: they are 54 inches, the underside of the wall cabinets, plus a 30, 36 or 42 inch wall cabinet. Choose a pantry the same height as the wall cabinets in the run and the tops of everything line up across the room, which is the reason the ladder was built that way.
