Bathtub Dimensions: Standard Sizes for Freestanding, Alcove, Soaking and Clawfoot Tubs

The short answer: a standard alcove bathtub is 60 in long × 30–32 in wide × 14–16 in high. Freestanding tubs run 55–72 in long × 27–36 in wide × 20–28 in high. But the number that decides whether you can actually soak in it is none of those — it is the water depth to the overflow, which is typically 4 to 6 inches shallower than the tub's interior height, and shallower still than its exterior height.

That gap is where most people get their tub wrong. This guide gives you all three numbers, not just the one printed on the box. Every figure we publish for our own freestanding tubs is taken off the factory drawing.

Quick reference: every common tub size

Exterior height on a freestanding tub includes the base. Water depth is measured from the lowest point of the basin floor to the lower edge of the overflow opening — the point past which water leaves rather than rises. Compare the figure across our full tub range.

The three depths nobody explains

Open any tub listing and you will find one height. There are three, and they are not close to each other.

1. Exterior height — floor to rim, including the base. This is what fits (or does not fit) under your window sill.

2. Interior depth — basin floor to rim. Always less than exterior height by the thickness of the base and the tub floor.

3. Water depth to overflow — basin floor to the bottom edge of the overflow hole. This is the only one that tells you how deep you will actually sit in water.

Here is what that looks like across our own tubs, measured from factory drawings rather than a tape measure:

NOCTARA loses 4 inches from exterior to interior, then another 2.4 inches to the overflow. A buyer reading "22 inches" and picturing 22 inches of water would be off by nearly a third.

This is not a quirk of one brand. A Home Depot Q&A on a competitor's tub put it plainly — asked whether the soaking depth was 17 inches or 13.78 inches, the answer was: "The soaking depth is 13.78″. The interior height is 17″."

And a 3-star reviewer on the same retailer, writing about a different tub:

"It gives a much larger appearance from the outside. When you are actually in it, the base is short, and the water level is not high."

What to do: before you buy any tub, ask the seller for the water depth to the overflow. If a listing does not publish it, treat the tub as unspecified rather than assuming the interior height is close enough.

Standard alcove bathtub dimensions

The alcove tub — three walls, one finished apron side — is the default in North American bathrooms because it matches the framed opening most homes were built with.

• Length: 60 in. This is the near-universal standard, sized to a 5-foot framed alcove.
• Width: 30–32 in. 30 in is most common; 32 in appears in newer builds.
• Height: 14–16 in, occasionally up to 20 in on deeper "soaker" alcove models.
• Compact versions: 48 in and 54 in, for bathrooms that were framed smaller. We do not make alcove tubs — our range is freestanding only.

If you are replacing an alcove tub, measure the framed opening, not the old tub. A 60 in tub needs a 60 in opening with roughly ¼ in of play — no more. Undersize the opening and the tub will not seat; oversize it and you are tiling a gap.

Freestanding tub dimensions

Freestanding tubs — also listed as stand alone bathtubs — are the loosest category, because nothing constrains them to a framed opening. Stand alone bathtub sizes and stand alone bathtub dimensions are quoted the same way as freestanding ones, so the two terms are interchangeable when you are comparing listings.

• Length: 55–72 in. Most sell between 59 in and 67 in.
• Width: 27–36 in.
• Exterior height: 20–28 in.
• Round models: 47–55 in in diameter.

Our freestanding bathtub range illustrates the spread: SYLARA is a 49.21 in round tub; ELVORA is a 67 in rectangle; NOCTARA is a 67 in two-person design at 39.4 in wide.

The number that gets ignored: base footprint. A freestanding tub does not sit on its full outline — it sits on a smaller base. That base is what has to land on solid, level floor, and it is often 10 or more inches narrower than the tub itself:

OBSIDIAN is a 59-inch tub standing on a footprint under 15 inches wide. If your floor slopes or you are tiling over an uneven subfloor, that is the contact patch that will rock.

Ask whether the tub has adjustable feet or a self-levelling base before you buy. Many solid-surface and stone resin tubs do not. A Houzz owner:

"It is a solid surface so there are not any leveling feet. I'm a little concerned with how much it rocks back and forth."

Soaking tubs: depth is the whole point

"Soaking tub" — or "soaker tub", the same thing — is a depth claim, not a shape. The working definition is a tub deep enough to cover the bather's shoulders when seated — in practice, a water depth of 15 in or more to the overflow.

Soaker tub sizes and soaker tub dimensions therefore cover the full length range, from 40 in to 72 in. Soaking tub width matters more than it does on an alcove tub: at 27–30 in wide your elbows touch both walls, while 32–36 in gives room to move. Our widest interior floor is VELISSA at 24.80 in across, inside a 67 in tub.

By that measure, a standard 14 in alcove tub is not a soaking tub regardless of what the listing calls it. Its water depth lands around 10–12 in.

Japanese soaking tubs (ofuro) are the extreme end: shorter in footprint, often 40–60 in long, but 28–36 in tall, with water depths of 22–27 in. They are designed for sitting upright with knees bent rather than reclining.

Practical rule for soaking tub dimensions: if you want water over your shoulders, look for 15 in+ to the overflow and check the interior floor length (below) so you are not sliding down to get there.

Interior floor: the dimension that decides comfort

A tub's exterior length tells you what fits in the room. The interior floor — the flat length and width at the bottom of the basin — tells you what fits you.

This is the least-published spec in the category and the one most responsible for "the tub is too big and I slide down" complaints. A 67-inch tub with a heavily curved interior can have a flat floor under 50 inches. We publish this figure for every model we sell.

Measured from our factory drawings:

Note LUNARA 61 in and LUNARA 65 in: the longer tub has the shorter interior floor (47.24 in vs 48.00 in) and a narrower one. Four extra inches of exterior length bought nothing usable. This is exactly why exterior length alone is a poor proxy for fit.

How to use this number: sit on the floor with your back against a wall and legs extended, and measure wall to heel. That measurement, minus 3–5 in for a slight recline against the backrest, is the interior floor length you want.

Clawfoot, drop-in and corner tubs

Clawfoot: 54–72 in long, 28–32 in wide, 24–30 in tall including feet. The feet add 6–8 in of height over a comparable freestanding tub, which raises the step-over. Water depth typically 14–18 in.

Drop-in: the tub shell only — it drops into a deck you build. 60–72 in long, 30–42 in wide, 18–24 in tall. Your finished dimensions are the deck's, not the tub's, so add 3–6 in per side for framing and surround material.

Corner: 48–72 in along each wall. Efficient on paper, but the triangular footprint wastes basin volume; a corner tub with a 60 in side often has less usable interior floor than a 60 in alcove.

We build freestanding models only — oval, rectangular and round — so the base footprint and interior floor figures in this guide are the ones that apply to them.

Clearances: how much space around the tub

Dimensions do not end at the tub. These are the gaps that make a bathroom work:

• In front of the tub: 24 in minimum of clear floor to stand and dry off. 30 in is comfortable.
• Behind a freestanding tub (wall side): this is the single most-asked question in freestanding tub forums, and the honest answer is a range, not a rule.
• Between tub and vanity or toilet: 12–18 in.
• Above the tub: if a window sits over it, confirm the tub's exterior height clears the sill.

On the wall gap, a Houzz owner who lives with one gave the most useful answer we have seen:

"I have 8.5″ on my long end and 3″ on the short end… I can get my vacuum hose back there no problem."

Working numbers: 4 in minimum on any side you need to clean behind, 6–8 in if you want it to be easy. Under 3 in and you will be moving the tub to clean, or not cleaning. Check the base footprint on the model you are sizing — that is the dimension the gap is measured from.

Drain position and rough-in

Getting the tub dimensions right and the drain wrong means opening the floor.

• Alcove tubs are sold as left-hand or right-hand drain, determined by standing in front of the tub facing it. Ordering the wrong hand is a common and expensive mistake.
• Freestanding tubs most often drain from the centre, through the floor. Our tubs use a Ø50 mm (1.97 in) drain outlet. Matching floor-mounted tub fillers are listed separately.
• Check thread size, not just outlet diameter. The gap between a 1.5 in and a 2 in drain assembly is the most common single failure point in freestanding tub installs. A Home Depot reviewer:

"The threads were not matching hooking the flexible pipe to the tub and it caused a leak which created water damage to my kitchen ceiling below which I had to have completely repaired. Check the threads!"

• Confirm what is in the box. Many freestanding tubs ship without a drain and overflow assembly, and the matching kit is sold separately.

Under the 2015 International Plumbing Code (IPC 407.1), bathtubs must conform to ASME A112.19.1, A112.19.2 or A112.19.3, or to CSA B45.5 / IAPMO Z124 — the latter covering plastic, solid-surface and resin tubs. Where UPC or IPC is enforced, an uncertified tub can be rejected at inspection regardless of its dimensions.

Measuring your bathroom in three steps

1. Measure the opening, not the old tub. For an alcove, wall-to-wall at floor level, at the rim height, and at the back — old framing is rarely square. Use the smallest number.

2. Measure the path in. Doorway width, hallway turns, and stair landings. A 67 in tub that clears the bathroom but not the stairwell is a return.

3. Mark the footprint on the floor. Tape out the tub's overall dimensions, then tape out the base footprint inside it. Stand in it. Open the door. Walk past it. Most sizing regret is visible at this stage and free to fix. Our ready-to-ship models list the base footprint alongside the overall dimensions.

Also confirm floor load. A 67 in tub holding 60+ gallons plus a bather concentrates a significant load onto a small base footprint. For cast iron or upper-floor installs, have the structure checked before ordering.

Five sizing mistakes that cause returns

1. Reading exterior height as soaking depth. Off by 4–8 in. Ask for water depth to overflow.
2. Ignoring interior floor length. A longer tub can have a shorter flat floor.
3. Forgetting the base footprint. The tub's outline is not its contact patch.
4. Ordering the wrong drain hand on an alcove tub.
5. Leaving under 3 in behind a freestanding tub. You will not be able to clean it. Check the base footprint on the model you are considering before you commit to a position.

Frequently asked questions

What is the standard bathtub size?

60 in long × 30–32 in wide × 14–16 in high, for an alcove tub. Freestanding tubs have no single standard and run 55–72 in long.

What is a standard soaking tub size?

There is no single standard. What defines a soaking tub is water depth to overflow — typically 15 in or more, versus 10–12 in for a standard alcove tub. Lengths run from 40 in (Japanese style) to 72 in.

How deep is a standard bathtub?

A standard alcove tub is 14–16 in tall on the outside, with roughly 10–12 in of water depth to the overflow. Deep soaker models reach 20 in exterior with 15–16 in of water.

What size freestanding tub do I need?

Measure wall-to-heel while seated with legs extended, subtract 3–5 in, and match that to the tub's interior floor length, not its exterior length. Then confirm you have 4 in+ of clearance on every side you need to clean.

Are freestanding tubs bigger than alcove tubs?

Taller and usually deeper in water, but not necessarily longer. Many freestanding tubs are 59–67 in against an alcove standard of 60 in. The difference is height: 20–28 in versus 14–16 in.

What size tub fits a small bathroom?

48 in and 54 in alcove tubs, or round freestanding tubs around 47–52 in in diameter — see SYLARA at 49.21 in. For layout help, read our guide to small bathroom design ideas. Check the base footprint and the clearance in front — a small tub in a room with no standing space in front of it still does not work.

Can I put a 60-inch tub in a 60-inch alcove?

Yes — alcove tubs are sized for it. Measure the opening at three heights first and use the smallest reading; older framing is often out of square by ¼ in or more.

What is the standard drain size for a bathtub?

The outlet is commonly 1.5 in or 2 in. Our freestanding tubs use a Ø50 mm (1.97 in) outlet. Confirm both the diameter and the thread specification against your drain assembly before installation — mismatched threads are the leading cause of post-install leaks.

Dimensions for Inyouths models in this guide are taken from factory production drawings. Where a drawing does not state a figure, we have left it blank rather than estimate. Water capacity figures are being re-issued by our factory to a single measurement standard (to the overflow) and are deliberately not published here until that is complete.