A door knocker should be about one-eighth to one-sixth as wide as the door. On a standard 820 mm Australian front door, that is 100-135 mm wide, fixed in the centre of the door at 1400-1500 mm from the floor.
There is no Australian Standard for door knocker size, so treat these numbers as a guide and not a rule. Before you buy, check three things: the size of the backplate, how far the knocker sticks out, and how it fixes to the door.
Door Knocker Sizes at a Glance
Use this table to match a knocker to your door width. Measure the door itself only, not the frame or side windows.
| Door Width | Typical Door | Knocker Width | Knocker Height |
|---|---|---|---|
| 720-770 mm | Narrow entry, cottage or terrace door | 90-125 mm | 100-150 mm |
| 820 mm | Standard Australian front door | 100-135 mm | 130-200 mm |
| 920-1020 mm | Wide entry door | 115-170 mm | 150-230 mm |
| 1200 mm and over | Oversized or pivot door | 150-200 mm | 200 mm and over |
If your door sits between two sizes, pick the larger knocker. A small knocker looks lost on a big door, but a larger one still looks good.
What Size Door Knocker Do You Need?
Start with the width of the door, then check the space where the knocker will sit. On a panelled door, the knocker goes on the flat timber between or above the panels, so measure that part too.
- Door width: aim for a knocker one-eighth to one-sixth as wide as the door
- Mounting space: leave at least 15-20 mm of flat timber around the backplate on all sides
- Door height: a standard door is 2040 mm tall; doors of 2340 mm or more suit a knocker from the larger end of the range
- Door thickness: most external doors are 40 mm thick, which matters for screw and bolt length
For example, a lion's head knocker with a 103 x 135 mm backplate is the right size for an 820 mm door. A 100 mm ring knocker also fits a standard door and looks more modern.
How High Should a Door Knocker Be?
Fit a door knocker at 1400-1500 mm from the finished floor to the centre of the knocker. This puts it at about eye level, where most adults can reach it with ease.
Put the knocker in the middle of the door, measured side to side. On a panelled door, fix it to the solid timber strip that runs between the top panels.
- Standard height: 1400-1500 mm from floor to knocker centre
- Above the handle: door handles sit at about 1000 mm, so the knocker sits 400-500 mm higher
- Doors with glass: fix to the solid timber only, never to the thin trim around the glass
- Doors with a letter plate: keep the knocker in the top half so the two are not too close
For handle heights and sizes on the same door, see the door handle sizes guide.
Door Knocker Projection and Screen Doors
Projection is how far the knocker sticks out from the door. Most knockers stick out 40-60 mm, and a lion's head knocker sticks out 55 mm.
This matters most if you have a security or fly screen door in front of the main door. Measure the gap between the two doors when both are closed, and make sure it is bigger than how far the knocker sticks out.
One thing people forget: a screen door hides a knocker and makes it hard to reach. If the screen stays shut most of the time, a bell fixed beside the door frame is a better choice.
Door Knocker Fixing Types
Door knockers fix on in three ways, and each way suits different doors. Check the fixing type on the product page before you drill anything.
| Fixing Type | How It Works | Best For |
|---|---|---|
| Face fix | Wood screws go through the backplate into the door face | Solid timber doors; the quickest fit |
| Rear fix | Bolts pass through the door from the inside into the knocker | A clean front with no screws showing; heavy knockers |
| Concealed fix | Screws hold a plate to the door, then the knocker covers them | Modern doors where no screws should show |
Solid timber and solid-core doors hold a knocker well. A hollow-core door has a thin skin that will not hold screws for long, so use a rear fix knocker with a backing plate inside or choose a bell.
Matching a Door Knocker to Your Home's Style
Size is only half the choice, because the shape should also suit the age and style of the house. Older homes suit knockers with lots of detail, while modern doors suit plain rings and simple shapes.
| Home Style | Knocker Style | Finish to Consider |
|---|---|---|
| Victorian and Georgian | Small Victorian or lion's head | Polished brass, antique brass |
| Federation and Edwardian | Federation or Edwardian pattern | Matt black, polished brass |
| Art Nouveau and Art Deco | Nouveau pattern with flowing lines | Antique copper, antique brass |
| Modern and coastal | Ring knocker or a bold modern design | Matte black, satin nickel, brushed brass |
Match the knocker finish to the handle, hinges and house numbers on the same door. Browse the full range of door knockers to compare shapes and finishes.
Door Knocker or Doorbell?
A knocker works well on a solid door in a small to medium home, where the sound carries inside. In a larger home, or behind a screen door, a bell is easier to hear and easier to reach.
Door knocker
- No wiring or batteries
- Adds charm to the door
- Needs a solid door to fix to
- Harder to hear in a large house
Doorbell
- Louder and easier to hear
- Can sit beside the door, clear of a screen
- Electric types need an electrician
- More parts to fit
Mechanical Turn Bells
A mechanical door bell fixes through the door, with a turn on the outside and the bell on the inside. A typical set has a 43 x 83 mm turn plate and a 90 mm bell, and needs no wiring or batteries.
Ships Bells
A ships bell mounts on the wall or porch post beside the door and rings with a pull cord. It is a good pick for a front porch, a side gate or a home with a screen door.
Electric Bell Pushes
An electric bell push is a brass button that is wired to a low voltage chime. The chime is sold separately, and a licensed electrician should do the wiring.
You can also compare every style in one place in the doorbells and knockers range.
How to Fit a Door Knocker in 4 Steps
1. Measure the door width and mark the centre line with a pencil. Then measure 1400-1500 mm up from the floor and mark the knocker centre.
2. Hold the knocker in place and check it sits on flat, solid timber. Mark the screw or bolt holes through the backplate.
3. Drill pilot holes for a face fix knocker, or drill right through the door for a rear fix knocker. Use a piece of scrap timber behind the door so the back face does not splinter.
4. Fix the knocker and tighten the screws by hand so you do not strip the holes. Knock a few times and check the knocker hits its metal plate cleanly.
If you are also rehanging or fixing the door, the door hinges guide covers hinge sizes and how to fix a sagging door.
Key Things to Check Before Buying
- Backplate size: it must fit on flat timber with 15-20 mm to spare all round
- Projection: it must be less than the gap to any screen door
- Fixing type: face fix, rear fix or concealed fix, matched to your door
- Door type: solid timber or solid-core is best; hollow-core needs a rear fix and backing plate
- Material: solid brass lasts well outdoors and comes in many finishes
- Finish: match the handle, hinges and doorstops on the same door
Note on unlacquered brass: an unlacquered brass knocker has no clear coat, so it is made to age. It will darken with use and weather, which is the look many older homes want.
Suggested Door Knockers and Bells
Lions Head Door Knocker, Polished Brass
$119.00
- Ring diameter 93 mm, backplate 103 x 135 mm, projection 55 mm
- Sized for a standard 820 mm front door, and big enough for a 920 mm door
- Solid brass, available in 8 finishes including antique brass and matte black
Small Victorian Door Knocker, Polished Brass
$56.00
- Slim solid brass design that fits the centre stile of a panelled door
- Available in 6 finishes, with matching centre door knobs
- Check the product page for exact dimensions before ordering
10cm Ring Door Knocker, Matte Black
$124.00
- 100 mm ring that suits standard and wide modern doors
- Rear fix, so no screws show on the front of the door
- Available in 8 finishes including chrome, satin nickel and signature brass
Sarlat Door Knocker, Brushed Brass
$284.00
- A large, bold knocker made to stand out on a wide entry door
- Concealed fix with face fix wood screws supplied
- Matching levers, pull handles and cabinet hardware available in the same design
Nouveau Door Knocker, Polished Brass
$99.00
- Solid brass with flowing Art Nouveau detail
- Available in 5 finishes, with matching centre door knobs
- Check the product page for exact dimensions before ordering
Plain Mechanical Turn Bell Set, Polished Brass
$109.00
- Turn plate 43 x 83 mm, bell 90 mm in diameter
- Fixes through the door with the spindle supplied; turn outside, bell inside
- No wiring or batteries needed
Small Ships Bell, Polished Brass
$84.00
- Solid brass ships bell in a classic style for the front porch
- Mounts beside the door, so it works with a screen door in place
- Available in a wide range of finishes and 2 sizes
Prices are correct at the time of writing and may change.
Frequently Asked Questions About Door Knocker Sizes
What size door knocker do I need for a standard front door?
For a standard 820 mm wide Australian front door, choose a knocker about 100-135 mm wide and 130-200 mm tall. This size looks balanced and does not crowd the door panels.
How high should a door knocker be mounted?
Mount a door knocker at 1400-1500 mm from the finished floor to the centre of the knocker. Centre it across the width of the door, on solid timber.
Is there an Australian Standard for door knocker size?
No, there is no Australian Standard that sets a size or height for door knockers. The sizes in this guide are based on what looks balanced and is easy to reach.
Can you fit a door knocker to any door?
A door knocker fits best on a solid timber or solid-core door. Hollow-core doors need a rear fix knocker with a backing plate, and glass doors will not work.
Will a door knocker fit behind a screen door?
Only if the gap between the two doors is bigger than how far the knocker sticks out, which is often 40-60 mm. If the screen door stays closed, a bell beside the door frame is a better choice.
What is the difference between face fix and rear fix door knockers?
A face fix knocker screws on from the front of the door. A rear fix knocker bolts through from the inside, so no fixings show on the front.
Should a door knocker match the door handle?
Yes, use the same finish for the knocker, handle, hinges and house numbers on the same door. Matching finishes make the entry look planned and tidy.
Related Guides
- Door Handle Sizes Guide - for handle height, backset and kit types to match your knocker finish.
- Door Hinges: A Guide to Sizes, Types and How to Adjust Them - for hinge sizes on heavy entry doors.
- Doorstops Guide - for stop types, sizes and fitting to protect walls behind the door.
