TLDR: The most common internal door in Australia is 820mm wide, 2040mm high and 35mm thick. Standard widths run 520, 620, 720, 770 and 820mm, with 870 and 920 available, and 2340mm is the common taller option for high ceilings. Frame your stud opening at roughly the door width plus 60mm. And no, the building code does not mandate a 2040mm door height, whatever half the internet says.
Replacing an internal door sounds like it should be simple. Measure the old one, buy the same size, hang it. Then you discover the old door is not a standard size, the opening is not square, and the door you bought is 5mm too wide to fit and 15mm too narrow to look right.
This guide sets out the actual standard sizes Australian manufacturers make, taken from their own published specifications rather than from other people’s blogs. It also clears up three things the rest of the internet gets wrong: the supposed legal minimum door height, the difference between the two accessibility width rules, and the gap between the size of a door and the size of the hole it goes in.
The short answer
The most common internal door in Australia is 820mm wide, 2040mm high and 35mm thick.
If you are replacing a door in a reasonably modern Australian home and you have not measured yet, that is the size it most likely is. But “most likely” is doing real work in that sentence, so measure before you buy.
Standard internal door widths
Australian door manufacturers make internal doors to a standard ladder of widths. Taken from the Hume Doors and Timber product catalogue and Corinthian’s current internal door range, the widths in common production are:
- 520mm. Linen presses, narrow cupboards and small storage.
- 620mm. Robes, cupboards, small store rooms and the occasional tight ensuite.
- 720mm. Bathrooms, toilets and laundries. Very common in older homes for wet areas.
- 770mm. A middle size, common for bathrooms and secondary bedrooms.
- 820mm. The standard for bedrooms, living areas, studies and most main internal doorways. This is the default.
- 870mm and 920mm. Wider doors, used where extra clearance is wanted, including accessible doorways.
Both manufacturers also produce narrower sizes for cupboard and cabinet applications. Hume’s Accent and moulded panel ranges list widths down to 410, 420 and 460mm, and Corinthian’s internal filter goes down to 330mm.
Corinthian’s current internal range spans a wider ladder again: 330, 380, 400, 420, 450, 460, 470, 520, 550, 620, 700, 720, 770, 790, 820, 870, 915, 920, 969, 970, 1000, 1020, 1200 and 1220mm. Most of those are specialist. The five you will meet in a normal house are 520, 620, 720, 770 and 820.
One quirk worth knowing: Hume’s internal door leaf ranges generally top out at 820mm, but its prehung jamb sets are listed for widths up to 870mm. If you are after an 870 leaf in a particular range, check availability before you plan around it.
Standard internal door heights
2040mm is the standard. It is by far the most common internal door height in Australian homes and it is the default across every manufacturer range.
2340mm is the common taller option, made for homes with raised ceilings. Hume lists 2340mm across its Humecraft, Hampton, Sorrento, Linear, Strata and Accent internal ranges. It has become much more common in newer builds where ceilings sit at 2700mm.
Beyond that you are into custom. Hume’s custom internal range runs from a minimum of 1990mm up to a maximum of 2400mm high. Corinthian lists heights including 1900, 1990, 2000, 2015, 2030, 2040, 2065, 2100, 2130, 2135, 2150, 2330, 2340, 2400, 2440 and 2450mm, though most are range-specific rather than universally stocked.
The 2040mm myth, and what the rules actually say
Here is the correction that matters, because it is repeated on a large share of the pages ranking for this topic.
There is no minimum internal door height in the building code for Australian homes. Several otherwise-useful pages state that the BCA or NCC mandates a minimum door height of 2040mm. It does not. 2040mm is a manufacturing convention that became universal because it suits standard ceiling heights and standard frame stock, not a legal requirement.
What the rules do prescribe is width, in one specific situation. The ABCB Standard for Livable Housing Design sets a minimum clear opening width for certain doorways in new homes. It prescribes clear opening width only. It contains no door height provision at all.
So if you are replacing a door in an existing home, there is no legal minimum size you have to meet. The standard sizes are what the industry makes, not what the law demands.
The two accessibility numbers, and which one applies to you
This is the other thing the internet routinely muddles. There are two different width figures and they belong to two different rules with two different scopes.
820mm applies to new homes. The ABCB Standard for Livable Housing Design states that internal doorways must provide a minimum clear opening width of 820mm, for doorways connecting to or in the path of travel to a habitable room or laundry on the entry level, an attached garage forming part of the access path, a toilet on the entry level, or a room containing a shower. It also requires at least one entrance door to the dwelling to have a minimum 820mm clear opening, and internal corridors connected to those doorways to be at least 1000mm wide. This applies to new Class 1a dwellings through the NCC, and Queensland adopted it from 1 October 2023 through the Queensland Development Code MP4.5 “Modern Homes”.
850mm belongs to AS 1428.1, the standard for design for access and mobility, and it applies to accessible paths of travel in public and commercial buildings. It is not a requirement for an ordinary house.
If you are renovating an existing home, neither figure is legally imposed on you. They are still the right numbers to design to if you want the house to work for a walker or a wheelchair.
Clear opening is not the same as door width
This is the single most useful distinction in this whole subject, and it trips up nearly everyone.
The clear opening is the actual gap you can move through when the door is open. It is narrower than the door leaf, because the leaf sits in a frame and the open door itself takes up some of the opening.
The Livable Housing Design Standard puts the relationship plainly: an 820mm clear opening width for a single swinging door can generally be achieved using an 870mm door leaf.
So if someone tells you that you need an 820mm door for accessibility, they have very likely confused the two numbers. You need an 820mm clear opening, and the leaf that delivers it is usually 870mm. On the same logic, the 850mm clear opening required in public buildings is typically achieved with a 920mm leaf.
For double, bifold or stacking doors, the standard allows smaller individual leaves provided the total clear opening still meets the minimum.
Door thickness
35mm is standard for internal doors. Confirmed across every Hume internal range and standard on Corinthian’s internal doors.
40mm is standard for external and entrance doors. Hume’s Haven and Verve entrance ranges are both specified at 40mm. Corinthian also lists 42mm in parts of its range.
Fire-rated and acoustic doors are typically thicker again. If you are replacing a door and the new one is a different thickness from the old, the hardware and the frame rebate both become issues, so check before you buy.
What size opening do you frame for?
If you are building a new wall or moving a doorway, the stud opening has to be bigger than the door to allow for the jamb, the packing and the operating gaps.
A reliable rule of thumb is door width plus about 60mm, and door height plus about 40 to 60mm.
So an 820mm door needs roughly an 880mm stud opening, and a 720mm door needs roughly 780mm.
The 60mm breaks down as roughly 20mm of jamb on each side, about 7mm of packing behind each jamb to allow the frame to be plumbed, and about 3mm of gap on each side so the door swings without binding. That breakdown is the useful part, because it tells you what to adjust if your jamb stock or your situation is different.
Published figures for this vary between 40mm and 80mm depending on who you ask, which is exactly why knowing the components beats memorising a single number. If you are working to a specific frame system, use that manufacturer’s figure.
Cavity sliders are a special case, and Queensland has its own number. Hume specifies the opening height for its cavity units as the door height plus 70mm in Queensland and Western Australia, and plus 80mm in New South Wales, Victoria, the ACT, South Australia and Tasmania. For the width, the flush pull unit is two door widths plus 10mm, and the flush jamb unit is two door widths plus 60mm.
Can you trim a door to fit?
A little, and less than you think. This is where warranties get voided.
Corinthian’s installation instructions state that a trimming allowance of up to 5mm is allowed on most doors, and that approximately 3mm clearance is needed at the top and sides, with 5mm at the bottom above the floor covering.
Hume’s warranty is stricter: a maximum of 3mm may be trimmed from any edge of the door, and it must be done evenly.
So the honest answer is that you can usually take a few millimetres off each edge, evenly, but the exact allowance depends on who made your door, and exceeding it can void the warranty. Check the manufacturer’s documentation for the door you actually bought. If the gap you are trying to close is 15 or 20mm, trimming is not the answer and you need a different size door or a reworked frame.
A related point most people miss: hollow core doors have a solid timber edge strip of limited width. Cut past it and you expose the hollow core, which cannot hold a hinge or a lock.
How many hinges?
Both manufacturers are specific about this and it matters more than people assume, because under-hinging is a common cause of doors warping and dropping.
Hume specifies that entrance and solid doors up to 2040 x 820 require three hinges, and larger doors require four hinges or a pivot system. It also notes that steel frames require three hinges to meet the guarantee for solid doors.
Corinthian’s installation instructions say to always hinge entrance and solid construction doors with a minimum of three 89mm hinges, to reduce the chance of warping.
Light hollow core internal doors are commonly hung on two hinges. Anything solid, heavy or tall should be on three.
How to measure your existing door properly
Measure the door leaf itself, not the opening, and measure it off the door rather than trusting what the previous owner told you.
Take the width at the top, middle and bottom, and the height at both edges and the centre. In an older home these will not all match, and the largest figure is the one that matters.
Measure the thickness at the edge, away from any moulding.
Then measure the frame opening as well, so you know how much clearance you actually have. And check whether the door is left or right handed, and whether it opens in or out, because that decides the hinge and lock set-up.
If the numbers do not land on a standard size, you have an older or a custom door. That is common in pre-1980s Brisbane homes, and it means either a custom door, a new frame, or a standard door fitted with the frame adjusted to suit.
Why old Brisbane homes rarely have standard doors
If you live in a Queenslander or a pre-1980s home and none of the sizes above match what you have measured, you have not measured wrong.
Standardisation came later than most of that housing stock. Doors in older homes were frequently made to the opening rather than the other way round, and generations of renovations, restumping and settlement have moved the openings since. Add Brisbane’s humidity, which swells and shrinks timber seasonally, and a door that fits in August can bind in February.
The practical options are a custom door made to your opening, a standard door with the frame adjusted or replaced to suit, or keeping the original door and repairing and re-hanging it. On a character home the third option is often the right one, because the original doors are usually better made than anything you can buy off the shelf.
Widening an existing doorway
If you are looking at these numbers because someone in the house needs more clearance, widening an existing doorway is usually achievable, but it is not a trim job.
Depending on the wall, it can involve checking whether the wall is load bearing, installing a lintel, reframing the opening, then patching plaster, replacing architraves, making good the flooring and repainting. That is several trades in sequence, which is why it is worth getting one team to scope the whole thing rather than starting with a carpenter and discovering the rest afterwards.
Frequently Asked Questions
What is the standard internal door size in Australia?
820mm wide, 2040mm high and 35mm thick is the most common internal door. Standard widths run 520, 620, 720, 770 and 820mm, with 870 and 920 also produced.
Is 2040mm a legal minimum door height?
No. This is widely repeated and it is wrong. The ABCB Standard for Livable Housing Design prescribes minimum clear opening width for certain doorways in new homes and contains no height provision. 2040mm is a manufacturing standard, not a code requirement.
What is the standard internal door thickness?
35mm for internal doors and 40mm for external and entrance doors, with 42mm also produced in parts of the Corinthian range.
What size door do I need for a bathroom or toilet?
720mm and 770mm are the usual sizes for bathrooms, toilets and laundries, though plenty of newer homes use 820mm throughout.
What size opening do I frame for an 820mm door?
Roughly 880mm wide, allowing about 20mm of jamb and 7mm of packing each side plus operating clearance, and about 40 to 60mm above the door height. Use your frame manufacturer’s figure if you have one.
Can I cut a door down to fit?
Only slightly, and the limit depends on the manufacturer. Corinthian allows up to 5mm; Hume’s warranty permits a maximum of 3mm from any edge, trimmed evenly. Going further can void the warranty and, on a hollow core door, can cut past the solid edge strip.
What door width do I need for a wheelchair?
You need an 820mm clear opening, which for a single swinging door is generally achieved with an 870mm leaf. That is the figure in the Livable Housing Design Standard for new homes, adopted in Queensland from 1 October 2023. The 850mm figure people sometimes quote comes from AS 1428.1 and applies to accessible paths of travel in public and commercial buildings.
Do I need a 2340mm door for high ceilings?
You do not need one, but it usually looks better. In a home with 2700mm ceilings a standard 2040mm door can leave an awkward expanse of wall above it. 2340mm is made across most major ranges for exactly this reason.
Why is my old door not a standard size?
Because it probably predates standardisation, or the opening has moved. This is very common in older Brisbane homes. You can go custom, adjust or replace the frame, or repair and re-hang the original door, which on a character home is often the better result.
How many hinges does my door need?
Light hollow core internal doors are typically hung on two. Solid and entrance doors up to 2040 x 820 need three, and larger doors need four or a pivot system.
Need a door measured, made or hung?
If the numbers are not adding up, we will come and measure the opening properly and tell you what actually fits. We install and repair internal and entry doors across Brisbane and Logan. Get a free quote or call 0485 814 802.