Door Frame Sizing Explained: What You Need to Know

Door frame sizing is essential for any builder, handy worker or DIY-er. Without a proper understanding of how door frame dimensions work together, you may end up with a door that is either too big, too small or just plain wrong. 

The most crucial door frame sizing measurement for anyone constructing a doorway between rooms or walls is the width of the Wall Opening Size, followed by four other critical door frame dimensions. 

To ensure you get the right door frame from Vincent Buda installed, we’ve put together a handy guide on everything you need to know about door frame dimensions and sizing. 

Standard Door Frame Dimensions

Although there are a variety of metal door frame sizes available online from Vincent Buda, the standard internal door frame dimensions are typically 2040 mm (height) by 820 mm (width) by 35 mm (thickness). 

The standard external door frame size is identical, except their thickness is 40mm. Although the standard door frame width is between 35mm and 40mm, custom door sizes can be much larger. 

Standard Door Height is 2040mm to 2340mm.

Standard Door Width is 820mm (range from 520mm to 920mm).

Standard Door Thickness is 35mm (internal) and 40mm (external).

Standard door frame sizing considers five critical factors:

• Wall Opening Size
• Frame Overall Size
• Reveal Size
• Door Size
• Clear Opening Size

Each of these door frame dimensions is outlined by Australian construction and manufacturing standards, each with different requirements for installation and application.

Wall Opening Size

The wall opening size is the largest dimension for door frame sizing. This dimension refers to the physical size of the wall opening where you will install the door frame and door. Wall Opening Size also takes into account floor clearance. 

Frame Overall Size

The second largest dimension is the Frame Overall Size. This measurement must be large enough to accommodate the actual door and its clearances, i.e. fitting inside the wall hole. There is typically a 5mm height and width gap between the wall opening size and the frame's overall size.

Reveal Size

The third largest dimension measures the space inside the frame where you will install the door. Reveal Size is the primary dimension we advertise on all our metal door frames, including fire-rated door frames.

Door Size

The fourth largest dimension is the size of the door: height, width, and door thickness inside the frame. Depending on the door type - fire doors and non-fire-rated solid core doors - there may be a discrepancy between the reveal size and door size. Fire doors, for example, have a tighter tolerance than a solid core door (less of a disparity between door size and reveal size).

Clear Opening Size

The clear opening size is the smallest dimension, which refers to the area required for some objects to pass through a doorway. You must document compliance with wheelchair accessibility requirements and the necessary fire and safety rules. Calculating this can be the most challenging because it relies on the thickness of the door, where the door stops, and how far the door can swing open.

What About Door Jambs?

A door jamb is another crucial part of any door for three reasons. 

Firstly, a door jamb is used to attach hinges to your door. Secondly, it holds the strike plate where the door’s latch meets. Without the door jamb, your door would not close properly. Attach the hinges on your door and hold the strike plate for the door’s latch. 

Door Jambs are also standardised to match standard door sizes in Australia. For example, the door jamb size for an 820 door is considered by the Reveal Size of your door frame.

Door Handle Height

According to the Australian Standard AS 1428.1, a door handle's height should be between 900 and 1100 millimetres above the ground, regardless of size. This standard is designed for mobility and accessibility. 

Fire-Rated Door Frames

All fire-rated door frames from Vincent Buda are rated up to 2 hours, depending on the type of door and the door hardware installed on the frame.

Fire Rated & Resistant Door Frame

Our single-leaf fire-rated door frames are suitable for 35-37mm doors and are supplied with the following specifications: 

• 3 x 100*75mm screw fix hinges supplied and fitted
• Made from 1.1mm Zincanneal
• One standard universal striker @ 1042mm high
• Assembled Unprimed
• 1 set of 10 x wire ties is provided with each brickwork or blockwork frame

Reveal Size Available:

• 2055 x 924 (To suit 2045 x 920 x 37 Fire Door)
• 2055 x 824 (To suit 2045 x 820 x 37 Fire Door)

Tube Fixed Metal Door Frame

All tube-fixed frames are fire-rated and available to suit a 35-37mm door. All frames have the following specifications:

• 3 x 100*75mm screw fix hinges supplied and fitted
• Made from 1.1mm Zincanneal
• One standard universal striker @ 1042mm high
• Assembled Unprimed
• 7 Tube Fixings per Stile (10 total per frame) 

Reveal Size Available:

• 2055 x 924 (To suit 2045 x 920 x 37mm Fire Door)
• 2055 x 824 (To suit 2045 x 820 x 37mm Fire Door)

Non-Fire Rated Door Frames

Metal Door Frame For Brickwork

Our single leaf non-fire rated frames for brickwork are designed for 820mm x 2040mm x 40mm solid-core doors only. All frames have the following specifications:

• 3 x 100*75mm screw fix hinges supplied and fitted
• Made from 1.1 Zincanneal
• A standard universal striker @ 1042mm high
• A deadbolt striker @ 1192mm high (if you do not require it, you can bog up the additional striker)
• Assembled Unprimed
• A set of 10 x wire ties is supplied with each brickwork or blockwork frame where stud clips have yet to be purchased.

Reveal Size Available:

• 820 x 2040 x 40mm solid core door

Single Leaf Door Frame

Our single leaf non-fire rated frames have the following specifications:

• 2 x 100*75mm screw fix hinges supplied and fitted
• Made from 1.1mm Zincanneal
• A standard universal striker @ 1042mm high
• Assembled Unprimed
• A set of 10 x wire ties is provided with each brickwork or blockwork frame where stud clips have not been purchased.

Reveal Size Available:

• 2065 x 724 (To suit 2040 x 720 x 35mm door)
• 2065 x 774 (To suit 2040 x 770 x 35mm door)
• 2065 x 824 (To suit 2040 x 820 x 35mm door)
• 2065 x 874 (To suit 2040 x 870 x 35mm door)
• 2065 x 924 (To suit 2040 x 920 x 35mm door)

Double Door Frame

Our double-leaf non-fire-rated door frames have the following specifications:

• 4 x 100*75mm screw fix hinges supplied and fitted (2 on either side of the frame)
• Made from 1.1 Zincanneal
• Assembled Unprimed
• A set of 10 x wire ties is supplied with each brickwork or blockwork frame where stud clips have not been purchased.

Reveal Size Available:

• 2065 x 1046 Double Door (To suit 2 x 2040 x 520 x 35mm doors)
• 2065 x 1246 Double Door (To suit 2 x 2040 x 620 x 35mm doors)
• 2065 x 1446 Double Door (To suit 2 x 2040 x 720 x 35mm doors)
• 2065 x 1646 Double Door (To suit 2 x 2040 x 820 x 35mm doors)

Standard Door Frame Sizes From Vincent Buda

You can trust Vincent Buda to have the appropriate metal door frame sizes for fire and non-fire-rated applications in stock and sent to your door. With 99% of our online products readily available anytime, orders placed before 12 pm will be delivered by ute or truck delivery the following business day.

Serving builders and DIYers since 1957, you can trust the Buda for your next job. Shop online now to access door frames and doors alongside high-quality structural steel and building supplies for various projects, big and small.