Calculator
Vertical storage capacity planner
Use this before buying shelving or bins for a closet, a wall or the space above a door. Enter the space and one container size, and it shows how many fit and how many tiers you would need for what you own. It updates as you type, and nothing leaves your device.
18 items fit
Worked example (shown when scripts are off): a space 72 in high, 36 in wide and 16 in deep, with 1 in shelves and containers 10 in high, 12 in wide and 16 in deep. Six tiers fit (6 times 10 plus 5 shelves of 1 inch is 65 inches), and 3 containers fit across each, so 18 containers in total.
Check before you buy
Measure the space yourself, use the outside size of the container, and check the load rating on the shelf or rack from the maker. Anchor tall shelving as its instructions say, and ask your landlord before drilling into walls.
How the planner works
It works in three steps. First, tiers: each tier needs the container's height, and each shelf between tiers takes its thickness, so n tiers need n times the container height plus n minus 1 shelf thicknesses. The planner finds the largest n that fits the usable height. Second, items per tier: the space width divided by the container width, rounded down, times the space depth divided by the container depth, rounded down. Third, capacity is tiers times items per tier.
If you enter how many you need to store, it compares that with the capacity and, when you are short, reports how many tiers you would need and roughly how much height that takes. If you also enter a weight and a shelf rating, it multiplies the items on one shelf by the weight of one and compares the result with the rating.
Worked example
With the default numbers, 6 tiers need 6 times 10 plus 5 times 1, or 65 inches, which fits in 72. A seventh would need 76 inches, which does not. Across the 36 inch width, three 12 inch containers fit, and one 16 inch container fills the 16 inch depth, so 3 per tier and 18 in total. Needing 14, you have room for 4 spare. Three containers at 8 each is 24 against a rated 40 per shelf, which is within range.
Limits to know
The planner assumes shelves can sit at any height, which is true for adjustable shelving but not for fixed ones. It ignores the lip of a shelf bracket, doors, slanted ceilings and anything in the way. It treats every container as the same size, so run it once for each size you plan to use. And it knows nothing about reach: the top tier may be hard to get to, so put rarely used things up there and heavy things low.
Weight and safety
The weight check compares your numbers only. The real rating depends on the shelf, the brackets, the wall and how it is fixed, so use the maker's rated load, never a guess. Tall, loaded shelving can tip if it is not anchored, which matters most with children or pets in the home. Renters should ask before drilling and can choose freestanding units or ones that stay inside a closet.
Where this comes from
The arithmetic is standard stacking and packing math, which we checked against hand calculations and a test run of many size combinations. The advice to anchor tall furniture to the wall follows the US Consumer Product Safety Commission's Anchor It campaign on furniture and TV tip-over, which we read about in published summaries. Using the maker's rated load rather than a guess is general good practice. We did not test any products.