Sleek, space-saving folding doors may seem like a novelty, but their roots go back centuries. They were initially a configuration for small spaces inspired by the folding screens and partitions used in traditional Japanese interiors.
Unlike traditional swing doors, this opening system consists of two or more slabs that fold together and slide toward the doorway. You can install them in the living room, bedroom, and kitchen, as well as in narrow spaces such as a corridor, wardrobe, pantries, or laundry. In addition, the models from the Louver collection allow air to circulate due to the horizontal slatted panels. Door Design Lab's product range includes over 600 Belldinni doors in various finishes (polypropylene, enamel, veneer, or primer), decorative elements, and sizes.
Nominal and actual door size
Before choosing and buying interior doors, it is crucial to understand the nominal and actual sizes.
The actual size is the true dimensions of the slab, i.e. the values that you can determine by yourself using a tape measure. The nominal size is rounded data that allows you to classify models into different size groups.
For example, you have measured that the slab is 23 ⅞ inches wide and 83 ¼ inches high. These values are called actual values. However, you need to purchase a bi-fold door with a nominal size of 24 x 84. This difference is usually about ½ inch and occurs due to allowances made for the installation, including space for hinges and tracks.
Standard bi-fold door sizes
Our assortment features modern bi-fold doors in all popular sizes so that every homeowner can find the right solution for their home or apartment.
Single bi-fold doors
Single bi-fold doors consist of one slab with two panels.
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Nominal height: 80, 84, 92 ½, 96, and 108''.
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Nominal width: 18, 24, 28, 30, 32, 36, and 42''.
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Thickness: 1 ¾ and 1 9/16''.
The most popular slabs are 24 x 80, 30 x 80, 30 x 96, and 36 x 96 inches.
The table shows the standard sizes of Belldinni single bi-fold doors.
Height 80
Height 84
Height 92 ½
Height 96
Height 108
Double bi-fold doors
Double bi-fold doors consist of two slabs with four panels.
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Nominal height: 80, 84, 92 ½, 96, and 108''.
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Nominal width: 36, 48, 56, 60, 64, 72, and 84''.
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Thickness: 1 ¾ and 1 9/16''.
The most popular slabs are 48 x 80, 60 x 80, 60 x 96, and 72 x 96 inches.
The table shows the standard sizes of Belldinni double bi-fold doors.
Height 80
Height 84
Height 92 ½
Height 96
Height 108
How to measure bi-fold doors?
Although sizing an interior door is one of the most critical stages in a renovation, it won't take you much longer if you clearly follow our detailed instructions in just three steps.
The tools you need
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Tape measure.
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Paper.
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Pen or pencil.
You can also record your measurements in notes on your phone.
Explore the doorway
Make sure that your doorway is level. To do this, measure the diagonal distance from the bottom left corner to the top right corner and vice versa. If both values are the same, your door opening is level.
Since the bi-fold configuration assumes that the doors will fold down, ensure that there is enough unobstructed space for them to do so.
Door width measurement
Here, you need to take three measurements and then, if they are different, write down the smallest one on paper:
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Place a tape measure on top of the door opening and measure the width from the left edge to the right edge.
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Repeat the action in the middle of the door opening.
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Repeat at the bottom.
To find out the correct width of the door slab, subtract one-half inch from the smallest value.
Door height measurement
Next, measure the height of the opening three times:
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Place a tape measure on the header on the left side of the opening and measure the height to the floor.
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Repeat the action in the middle of the doorway.
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Repeat on the right side.
As in the previous step, subtract one-half inch from the smallest number.
Size chart for bi-fold doors
All measurements in the table are in inches.
Nominal slab width
Actual slab width
Door opening width
Nominal slab height
Actual slab height
Door opening height
FAQ
In this section, we have compiled answers to frequently asked questions to make the door sizing process as easy as possible for you.
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What size bi-fold door do I need?
The dimensions of the slab depend on the size of your doorway. Please follow our step-by-step guide to take measurements.
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What is the standard bi-fold door size?
Most popular sizes:
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For single bi-fold doors — 24 x 80, 30 x 80, 30 x 96, and 36 x 96''.
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For double bi-fold doors — 48 x 80, 60 x 80, 60 x 96, and 72 x 96''.
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What is the smallest bi-fold door size?
The smallest of the standard sizes is 18 x 80''. We also offer doors with non-standard heights and widths.
Conclusion
We recommend double-checking your measurements to avoid mistakes and to choose a slab perfectly sized for your opening. Once you know the dimensions of slabs, contact our specialists to order bi-fold doors or use the convenient configurator on our website, which will take into account all the necessary parameters.