Bathtub Sizes in Australia: A Complete Guide

Description: An overview of the main bathtub types — alcove, freestanding, drop-in and corner — helping readers understand their options before choosing the right bath size and dimensions for their Australian bath
Video Credit: The Home Depot

Standing in a bathroom showroom, staring down rows of bathtubs with absolutely no idea which size to go for — yeah, that's a pretty common experience. It gets overwhelming fast. Getting the exact dimensions sorted before you buy sounds dead simple — until you're actually standing there with a measuring tape, trying to make sense of it all. I've been through the whole process myself, so I can vouch for it — and the one thing I really wish someone had told me earlier is that bathtub sizes in Australia follow pretty predictable standards.

Standard Bathtub Sizes in Australia

For an Australian home, the standard bath size runs 1500mm in length, 700mm to 800mm across, and anywhere from 350mm and 500mm deep. For adult bathing, 1500mm is really the practical floor — go any shorter and you'll know about it. Newer builds quite often centre the bathroom layout around a 1700mm bath — it's a noticeably more comfortable soak, yet the floor footprint barely changes.

Worth noting: American and British specs use the imperial system, so the numbers there won't match. Everything here is in metric — the same figures your plumber and waterproofer will reference, no matter which Australian state or territory you're in. Across every Australian state and territory, a licensed plumber must handle the water supply and waste connections — factor that into your reno budget from the start.

Diagram of four bathtub types with millimetre dimensions: freestanding, alcove, drop-in, under-mount

Bathtub Dimensions by Type

With the baseline measurements for a standard Australian bath sorted, it's worth looking at how those dimensions vary across the different bath types available.

Freestanding bathtubs are the ones that stop people mid-scroll in every home magazine — and honestly, the appeal is real. Lengths generally fall between 1500mm to 1800mm, and widths sit at 700mm to 800mm. Bear in mind that 1800mm of clear floor space is the minimum for these to work — so no matter how good they look, a smaller bathroom just won't cut it.

Alcove and built-in bathtubs are the reliable backbone of Australian bathrooms — practical, space-smart, and available across a solid range of dimensions. Drop-in styles — where the bath sits inside a tiled deck or hob — generally measure 1400mm to 1700mm in length, and there are a couple of compliance requirements to sort out before any tiles go down. Under (AS 3740:2021) and (NCC 2022, ABCB Housing Provisions, Part 10.2), the walls around any built-in bath must be waterproofed to 150mm above the rim — your waterproofer will be across this, but it's good to know before tiling starts.

On the cost side, drop-in bathtubs are hard to beat — entry-level models start from around $312. Acrylic baths usually come in at no more than 30kg, so they're manageable on delivery day — stone resin models, though, can push past 100kg before a drop of water goes in. Broadway and Poseidon both have solid ranges in this space, with Broadway holding a particularly strong foothold across multiple bath categories in Australia.

Person in black crouching to measure a floor with a yellow tape measure

How to Pick the Right Bath Size for Your Bathroom

Spec ranges only mean something once you hold them up against the actual space you've got.

Measure the floor area and tape out your proposed bath footprint with masking tape — it sounds basic, but it's genuinely one of the most useful steps you can take. A 600mm clearance walkway beside the bath is the minimum you should allow. Don't forget the door swing either — a bath that looks perfect on the plan can make the entry completely unusable if door clearance hasn't been factored in. For bathroom doorways in new builds, the 820mm minimum clear opening set out in (NCC 2022, ABCB Housing Provisions, Part 12.2) is a handy benchmark to carry into renovation work too.

Before you order a thing, confirm where your rough-in waste sits. Getting a bath delivered only to find the waste point is in the wrong spot for your existing plumbing is a costly mistake — and a completely avoidable one.

Compact bathroom with aged brass taps, small built-in bath and patterned floor tiles

Baths for Small Bathrooms

Just because you only have a small amount of floor area available does not mean you should rule out having a bath. There are space-saving solutions specifically designed with a small footprint — it is quite possible to have a small bathroom with bath in Australia. Japanese-style soaking tubs can be as short as 1200mm long but tend to be deeper than an ordinary bath, at around 500mm depth, and are intended for sitting rather than lying down. A shower-bath combo unit takes space-saving to the extreme by performing double-duty within the same footprint. Alcove drop-in units from 1400mm to 1500mm length are generally quite compact, with entry-level options starting from around $312.

Cream marble bathroom with corner bathtub, wall-mounted toilet, sink, and chrome towel rail.

Corner Bath Tubs

You may wish to consider fitting a bathtub in corner position, which can provide more clear floor space overall than a standard alcove linear installation. Corner bath tubs have a minimum footprint of 1200mm × 1200mm and are also available in 1400mm × 1400mm and 1500mm × 1500mm sizes. Broadway and Poseidon both offer corner bath tubs in Australia, with prices ranging from $958 to $2,085. Corner bath tubs tend to cost more not only because of the extra floor space involved but also because a hob is typically built into the floor area and must be tiled over to match the bath rim height. They also require a different rough-in waste position than an alcove unit. Confirm your rough-in waste position with your licensed plumber before proceeding with any waterproofing. All adjacent walls and the hob must be waterproofed by a licensed waterproofer, and nothing should be tiled until the waterproofing is inspected and passed.

References

State plumbing licensing legislation (VBA Victoria; Fair Trading NSW; QBCC Queensland; Building Practitioners Board WA; CBOS Tasmania; ACTPLA ACT; Building & Energy SA; ABPB NT)

AS 3740:2021 Waterproofing of Domestic Wet Areas, Standards Australia

National Construction Code 2022, ABCB Housing Provisions, Part 10.2 Wet Areas

National Construction Code 2022, ABCB Housing Provisions, Part 12.2 Livable Housing

FAQs

Once the bath arrives, how long does a typical installation actually take?

A licensed plumber can usually knock over the rough-in connections for a standard alcove or drop-in job in half a day — but the full run of waterproofing, curing, and tiling will commonly stretch across three to five working days. Freestanding and corner installs usually take longer — waste positioning is less predictable, and the surrounding finishes need more careful sequencing.

Will pulling out an old bathtub damage the waterproofing membrane beneath it?

Almost always, yes. When you lift out an existing bath, the membrane beneath and around it almost always gets disturbed or breached — so the waterproofing has to be completely redone before the new bath goes in, not just touched up. It's one of the more common — and expensive — shortcuts taken in bathroom renos.

Do acrylic and stone resin baths differ much in weight, and what does that mean for floor prep?

Acrylic baths are much lighter, often sitting under 30kg, while stone resin models can push past 100kg before any water goes in. For older homes with timber subfloors, it's worth having a structural check done before a heavier bath goes in — your builder or certifier can usually give you a quick answer.