How the shelf count is produced
Take the interior height, subtract the hanging section and the top and bottom clearances, and what remains is the zone available for shelves. One tier occupies the board thickness plus the gap above it, so dividing the zone by that figure and rounding down gives the number of shelves that fit. The leftover height is reported too, which shows whether trimming the gap slightly would let another tier in.
The hanging height and the shelf gap are figures you supply. No recommended heights are published here for either, because widely repeated numbers reflect garment lengths and shop habits rather than a standard. Written as of October 2026.
This tool handles dimensions only. It does not cover board strength, sag, load or pricing. Confirm anything you intend to build with the manufacturer or an installer.
Frequently Asked Questions
No recommended height is published here, because it depends on the length of what you hang and where the rail sits. Enter your own figure and the page works out shelves from the height that is left.
You cannot install half a shelf, so counting what fits uses rounding down. The height left over is shown separately, which tells you at a glance whether another tier would almost fit.
Thickness is the board itself, and the gap is the open height from the top face of one shelf to the underside of the next. One tier is treated as those two figures added together.