Step 1: Measure the door width

Take three measurements inside the door frame – at the top, middle and bottom. The widest measurement determines the width of the door. Ensure the door measurements are taken from the frame rebate.

• Use a tape measure to understand the width of the three areas of the door frame. Run the tape measure along the width of the frame from the left to the right and record these numbers.
• The standard AU widths of doors are: 520,620,720,820,920mm. These may vary as the current door frame or door may be custom.

Step 2: Measure the door height

Measure the inside of each vertical side of the frame. The longest length determines the height required. The allowance for the floor covering should be also considered when measuring.

• Use a tape measure to understand the height of the door frame. Run the tape from the top corner to the bottom corner on each side and record the number of the longest length.
• The standard AU height of doors is most commonly 2040mm, however depending on the design it could be 2340mm or a custom size.

Step 3: Measure the door thickness

If replacement doors are being considered and the same frames are being used,  then you will need to replicate the door thickness, so make sure to take this measurement also.

• Use a tape measure to understand the thickness of the existing door. Run the tape measure along the edge of the door and record the measurement of the thickness.
• You should also measure the rebate in the frame, where the door sits when closed.
• The most common door thicknesses are usually 35,40,45mm. Fire doors would be approximately 38 or 46mm.