What Backset Do I Need for a Door Handle? The Australian Guide
Written by the Prime Hardware showroom team, Annangrove NSW · Last updated 11 August 2026
The backset is the distance from the edge of the door to the centre of the spindle hole — the hole your handle's square bar passes through. In Australia, 60mm is the standard backset for internal doors with tubular latches. If you're replacing an existing handle, measure your current backset and match it; if you're fitting a new door, choose 60mm unless the door has a narrow stile or you're fitting a mortice lock.
That's the short answer. The rest of this guide shows you how to measure it correctly, which sizes exist and where each one is used, and the special cases — mortice locks, narrow-stile doors and rebated double doors — where the standard answer doesn't apply.
How to measure backset on an existing door
Open the door and look at the edge — the narrow face where the latch plate sits. Measure from that edge to the centre of the hole the handle spindle passes through (with the handle still fitted, measure to the centre of the spindle or lever hub). That distance is your backset.
Two mistakes cause most wrong orders. First, measuring to the near side of the hole instead of its centre — always measure to the centre. Second, measuring from the face of the door instead of the edge — backset is always measured from the door edge, on the same plane as the latch travels.
If your measurement lands on roughly 60mm or 70mm, you have a standard prep and any Australian handle set in that backset will fit without re-drilling. If it lands on an odd number like 48mm or 55mm, you likely have an older or imported lock — measure twice and check the special cases below.
Australian backset sizes at a glance
| Backset | Mechanism | Where you'll find it |
|---|---|---|
| 60mm | Tubular latch | The Australian standard. Most internal passage and privacy sets in modern homes. |
| 70mm | Tubular latch | Entrance doors and wider-stile doors, where the handle sits further from the edge for knuckle clearance and visual balance. |
| 45mm | Tubular latch | Narrow-stile doors — French doors, glazed doors and some heritage doors where a 60mm latch would break through the stile. |
| 44mm / 46mm / 57mm | Mortice lock | Entrance and locking doors fitted with a mortice lock rather than a tube latch. The backset is fixed by the lock case, not the handle. |
Handles themselves don't have a backset — the latch or lock does. When you buy a passage or privacy set, the included latch determines the backset, which is why most Australian sets ship with a 60mm latch as standard and offer 45mm or 70mm on request.
Mortice locks: the backset belongs to the lock case
If your door has a mortice lock — a lock body sunk into a pocket in the door edge, common on entrance doors and heritage homes — the backset is built into the lock case and typically measures 44mm, 46mm or 57mm depending on the model. You cannot change it by choosing a different handle. When replacing a mortice lock, measure the existing case's backset and match it, or be prepared to re-chisel the mortice pocket and re-drill the door. When replacing only the furniture (levers or knobs) on an existing mortice lock, backset doesn't matter — the new furniture simply needs to suit the lock's spindle and cylinder positions.
Special cases
Narrow-stile and glazed doors. Measure the stile (the solid timber or aluminium between the glass and the door edge). If a 60mm latch would leave less than about 15mm of material behind the latch tube, step down to a 45mm backset. Aluminium sliding and security doors use their own shorter-backset mechanisms again — treat those as a separate category and match the existing hardware.
Rebated double doors. Where a pair of doors meet with an overlapping rebated edge, the latch needs a rebate kit to suit the stepped edge — the backset rules above still apply, but order the rebated version of the latch or lock.
Renovations and retrofits. The cheapest door upgrade is one that reuses the existing holes. Match the existing backset and check the rose (the round or square plate behind the lever) is large enough to cover the old footprint. Some ranges offer larger roses or adapter plates specifically to cover previous hardware marks.
Backset vs the other measurements you'll see
Product listings mention several measurements, and they're easy to confuse. Backset is door edge to spindle centre — covered above. Door thickness matters for fixing-bolt length; most Australian internal doors are 35mm and entrance doors 40mm. Rose diameter (commonly 50–65mm) determines whether the handle covers existing marks. Latch case length is how deep the latch body extends into the door — it follows from the backset and rarely needs separate checking on standard doors.
Frequently asked questions
What is the standard backset in Australia?
How do I measure backset without removing the handle?
Can I put a 60mm latch in a door drilled for 70mm?
Does backset affect which handle style I can choose?
What backset do I need for a mortice lock?
Still not sure? Bring a photo of your door edge and your measurement into our Annangrove showroom, or call 1800 329 028 — matching a backset takes our team about a minute. Browse door handles, latches and mortice locks with backset options listed on every product.