Choosing a Sink — and the Cabinet That Has to Hold It

The width of the base is the first decision, not the last

The working rule: the sink base is at least 3″ wider than the sink’s outside dimension. A 33″ sink wants a 36″ base; a 30″ sink wants a 33″. That is not caution for its own sake — it is what is left once the box has taken its share.

A frameless base is two panels and a space. On a 36″ box with ¾″ sides the clear interior is about 34½″, so a 33″ sink leaves roughly ¾″ of air per side — no room for a fabricator’s tolerance, an installer’s hands, or the clips of an undermount. Drop to a 33″ box and the interior is 31½″: the sink will not pass between the sides at all.

Measure the outside dimension, not the bowl. A sink sold as 33″ is 33″ across the outer edge and its bowl might be 30″. Retail listings quote the two interchangeably; the spec sheet does not.

Front to back gets forgotten. A base is 24″ deep with a top at about 25″, so a sink over 22″ front to back leaves nothing behind it for the tap deck and nothing in front for a wrist. Most sinks land between 18″ and 22″, which is no accident.

Four ways a sink meets the counter, and what each one asks for

Mounting is not a style choice. It runs both ways — the mounting decides which worktops are allowed, and the worktop decides which mountings are allowed. Settle it with the counter, not after.

One bowl or two, decided by what you actually wash

Here is the arithmetic nobody does. In a 33″ sink, a double gives two bowls of roughly 14″ each once the divider and the walls have taken their cut. A half-sheet pan is 18″ long and an oven rack is longer. So a double will never lie a baking tray flat, and you will wash it on edge, slopping water down the cabinet front.

A wide single solves that and gives up something real: nowhere to keep one side clean while the other soaks, nowhere to stand a colander while the tap runs. With a dishwasher, where the sink is mostly rinsing and filling pots, single wins easily. If you hand-wash most things, the wash-and-rinse split is a working method, not nostalgia.

The honest middle is the offset double: one large bowl for the tray, one narrow bowl of 12″ or so for the colander. Low-divide sinks drop the divider a few inches below the rim, so a tray lies across it while two zones still work below.

• You have a dishwasher and mostly rinse, scrape and fill pots. Single bowl, as wide as the base allows.
• You wash roasting trays, oven racks and sheet pans by hand. Single, no argument. A divider is the enemy of everything flat.
• No dishwasher, and there never will be one. Double, two equal bowls, wide landing counter on the dirty side.
• You want to soak one thing while the sink stays usable. Offset double, or a low-divide bowl.
• You prep on an island away from the main run. A dedicated 15″ to 18″ bowl — but allow for a base cabinet, a waste and a supply, because it is a second plumbing point in the middle of the floor. The island chapter covers the cost in storage.

How deep before it starts to hurt

Eight inches was the old default and it is still the kindest to your back. Ten is what the showroom sells you: it hides an evening’s washing-up below the rim, takes a stock pot upright under the tap, and keeps water in when you rinse hard. Nine is the compromise, and what we would pick if nobody had a strong opinion.

What the extra two inches cost is a lean. Set a 10″ bowl in a 36″ counter and the drain sits roughly 24¾″ off the floor once the top’s thickness is allowed for. Reaching it means bending from the waist, every wash-up, for years. If the main cook is under about 5 ft 4 that is a real reason to go shallower — and if the counter is at a non-standard height, do the sum before choosing the bowl. The standard heights are here.

What they search at midnight “kitchen sink depth 8 vs 10” — usually while standing at the old sink, trying to work out whether the ache is the bowl or the counter height. Often it is the counter.

The second cost is inside the cabinet. A frameless base has about 34½″ of internal height; take 10″ of bowl out of the top and under 25″ is left for the strainer, the tailpiece, the trap, a disposer and anything you hoped to store. Deep bowls and full cabinets compete directly.

Which is why the drain position earns more attention than it gets. A rear-set waste is the best thing you can do for the cabinet underneath: the trap moves back and up, and you get a usable rectangle of floor instead of a plumbing sculpture. If a sink you like offers both, take the rear drain.

What it is made of, and how it behaves on a bad day

Start with stainless, because most kitchens end there and the numbers get misread. Gauge runs backwards: the smaller the number, the thicker the steel. Twenty-two gauge is about two-thirds the thickness of eighteen, and sixteen is a quarter thicker again. Eighteen is the sensible floor — below it the base drums under the tap and dents when a pan lands.

Gauge is not the whole story, though; the trade leans on it because it is the one number that fits on a label. The pads glued underneath do more for noise than another hundredth of an inch of steel. Grade matters too: 304 stainless, sometimes marked 18/10, resists corrosion properly, while cheaper 201 stains around the drain in hard water. And take brushed over mirror polish — every stainless sink scratches, and brushed absorbs them into an even sheen within a month.

One thing the table cannot hold: hard water changes the ranking. If your kettle furs up in a fortnight, a dark composite will bloom white and you will be drying it daily. Choose the worktop alongside the sink, because to your hands they are one surface. We compared worktop materials here.

Where it goes in the plan, and what it has to be next to

Put it under a window if the room offers one. Not for any ergonomic reason — you stand there longer than anywhere else in the kitchen, and staring at a wall for that long is a slow, unnecessary misery. The trade is that a window kills the wall cabinet above, so that storage has to reappear somewhere, and the tap has to clear a sill.

Landing space is what separates a sink that works from one that does not: 24″ of clear counter on one side and 18″ on the other. If the wall gives you only one, put the 24″ where dirty things arrive — that is where a stack of plates and a roasting tin actually land.

Never set a sink hard against an inside corner. You cannot stand square to it, so you wash at an angle with one shoulder dropped, and the cabinet’s door will argue with the return run. Keep the centre of the bowl at least 15″ from the corner and check the two doors clear each other. Corner cabinets have their own chapter of grief.

The dishwasher has to be immediately beside the sink base — not near it, beside it. The drain hose has to reach the sink’s waste and it usually takes water from the same stop under the bowl. Most hoses run around 5 ft, and extending one is a plumber’s conversation, not an install-day decision.

Which side is the real argument, and there is no single answer. The usual advice puts the machine to the left for a right-handed person: scrape and rinse with the right, load with the left. Plenty of confident right-handers loathe that. The test takes four minutes — stand at your current sink with a stack of plates and mime the whole cycle twice, once with a machine on each side.

• 24″ one side, 18″ the other — of clear counter, wide side where dirty dishes land.
• 15″ minimum from an inside corner — to the centre of the bowl, so you can stand square.
• Dishwasher immediately adjacent — the hose has to reach, and its open door takes 24″ of aisle.
• Draw the window trim, not the opening — the casing is what the tap and the uppers actually hit.
• Confirm where the waste and supply already are — moving the sink two feet along the wall is a plumbing job, better decided now than discovered later. It is on the layout mistakes list.

Six things that go wrong inside that cabinet

The sink base is the busiest cabinet in the kitchen and the only one where three trades meet. Almost every complaint about a finished sink is really about the box under it.

• The disposer that ate the drawerA working drawer under the bowl is lovely, right up until a food waste disposer and a trap claim the middle third of the box.FixDecide the disposer before the cabinet. If the drawer matters more, specify a rear-set drain, a shallower bowl and a drawer box notched around the plumbing — or accept a false front from the start rather than on install day.
• The trap that cannot fallWaste runs downhill or it does not run. The drain stub usually sits 18–20″ off the floor; a 10″ bowl puts the underside of the sink at roughly 24¾″, and a disposer’s outlet hangs 6–9″ below that — which can land level with the stub or under it. Water then sits in the disposer and smells.FixDo the arithmetic before the wall closes: bowl bottom, minus disposer, has to stay above the stub. If it does not, the stub moves — nothing before drywall, a day and a tiler afterwards.
• The tap that hits the windowA pull-down tap is often 15–18″ tall, and a rear-mounted single lever needs 2–3″ of clear air behind it to reach fully open. Under a window, that air is the sill.FixMeasure the tap at its open position against the sill height and the path of the sash. If it is tight, use a side-lever tap, a shorter body, or move the tap onto the wall.
• The undermount that let goClips epoxied to the underside of a stone top are a positioning device, not a structural system. A large double bowl filled to the rim holds enough water to weigh about as much as an adult, and the counter should not be carrying that.FixAsk what holds the sink from below — a plywood cradle, or rails fixed to the cabinet sides. For fireclay and cast iron it is not optional: those never hang from the worktop.
• The farmhouse sink specified after the cabinetsThe most expensive sequencing error on this page. An apron sink needs a base built for it and a standard base cannot be converted — so the answer is a new cabinet in the same colour and door style, arriving weeks after everything else.FixChoose it in the same conversation as the cabinets, spec sheet open. If you are only considering one, say so before the order goes in.
• The filter with nowhere to liveAn under-sink filter housing needs vertical space plus room to swing down and off to change the cartridge. Add a reverse-osmosis tank and there is a football in there too, competing with the disposer, the trap and the bin.FixDraw the filter, tank, disposer, trap and bin in one cabinet before buying any of them. And the waste and supply come through the back panel: on a frameless box with mounting rails, cut between the rails, never through one. The install chapter covers the rails.

Tap holes, and the last moment you can change your mind

On a drop-in, the holes are punched into the deck at the factory, so the count is fixed the day you buy the sink. On an undermount they are drilled through the stone in the fabricator’s shop, so the count is fixed at template. Either way there is a moment after which adding a hole means a new sink or a new piece of worktop.

So count them on paper. A single-lever tap is one hole; separate hot and cold handles are three. Add one each for a side spray, a soap dispenser, a filtered-water tap, a disposer air switch, instant hot water. A blank cap in an unused hole looks fine; a new hole in a finished top means a fabricator’s visit and a held breath.

Two deserve their own sentence. An air switch is a deck button that runs the disposer on a puff of air — the tidy answer when the sink is in an island with no wall for a switch. A wall-mounted tap frees the whole deck so the counter behind the sink wipes in one pass, at the cost of moving the plumbing into the wall: a rough-in decision, taken early. And check the spout’s reach, not just its height — with a 22″ sink and a rear drain, a short spout washes the near rim and nothing else.

Then, before anything is ordered, run this:

• The sink’s spec sheet, printed — outside width, front to back, depth, minimum cabinet size, drain position.
• The base width taken from that sheet — not from the 3″ rule, which was for sketching.
• Mounting matched to the worktop — undermount only on stone, quartz, porcelain or solid surface.
• Tap chosen, holes counted, spout reach checked — before the top is templated.
• Disposer, filter, trap and bin drawn in one cabinet — on one sketch, competing for one space.
• Stub height checked against bowl depth plus disposer — while the wall is still open.
• Landing space both sides, dishwasher on the side you tested — 24″ and 18″.
• Delivery confirmed before template day — an undermount cannot be templated from a photograph.

One honest limit. Everything above is planning you can do with a tape and a spec sheet, and it catches most sink problems before they cost anything. What it will not do is size a waste run, move a stack, or tell you whether that wall can take a wall-mounted tap. Drain falls, vents and anything inside a wall belong to a licensed plumber — and the good ones would far rather see your drawing before the cabinets arrive than your cabinet after.