Ideally the door will cover 2 to 3 inches beyond the opening on each side.
Barn door measurements.
Do this by measuring from the left to the right side of the door.
Exterior door sizes may even be larger.
If the doorway has moldings measure from outside edge to outside edge to determine the proper door width add about 4 to 6 inches to your measurement.
Measure across for the width and from the top of the casing molding to the floor for height.
Measure the door width.
Sheetrocked opening no trim or casing width.
The average door width ranges from 24 inches to 36 inches.
How to measure for a barn door in three steps.
Using a tape measure begin at the left edge of the opening and measure straight across to the right edge.
Barn door opening measurements while the style of barn door you choose will come down to your personal preference you will need to be aware of barn door vs opening dimensions when making your choice.
Measure from inside to inside of the opening.
Barn door measuring guide for door openings with casing molding.
Your door s width should be 2 to 3 inches wider than the door opening and 1 inch higher than the dimensions of your opening.
Total door width will be 36.
In this example the opening width is 32 4.
Generally most standard barn doors are approximately 36 x 84 or 42 x 80 with enough extra lip to overlap most standard door frames 36 x 80 by an inch or so.
Add 4 to the measurement and you have your recommended door width.