Tool · Storage space calculator
A closet storage capacity calculator that turns a shelf's measurements into a real box count.
Type in a width, height and depth in centimeters. Pick how tight the fit needs to be and choose a box size from the catalog, and the math runs right there on the page, not hidden behind the button.
Measure the actual opening
Measure the shelf or closet at its narrowest point on each axis, not the widest — a closet with a door frame trim that juts in two centimeters on each side effectively loses four centimeters of usable width, and boxes do not compress to fit a door casing. Height should stop at the underside of the shelf above, or the ceiling if there is no shelf above it. Depth is the wall-to-front distance, not the depth of the door swing.
The fit-tightness setting exists because raw volume never equals usable volume. Brackets eat into the corners, boxes do not stack edge-to-edge without a gap for a hand to grip them, and an awkward corner near a door hinge is often unusable at any box size. Loose accounts for the most lost space, Tight assumes a careful, deliberate stack.
Run the numbers
Fill in the three dimensions, choose a fit setting and a box size, and the usable volume and box count update below.
A 90 × 180 × 40 cm closet at a standard fit holds about 486 litres, or roughly 22 kraft boxes.
Priced per box, lower basis at four or more
See the kraft storage boxesThe formula, in full
usable_litres = width_cm × height_cm × depth_cm × 0.001 × fit_factor
box_count = floor(usable_litres ÷ box_volume_litres)This gives a planning figure, not a guarantee that a given box physically maneuvers into every corner. Odd-shaped alcoves and low headroom above a shelf can still cut into the real count.
Reading the result
Usable litres is the volume left after the fit factor, not the raw box shape of the space. Box count is that figure divided by the chosen box's volume and rounded down, because a box that does not fully fit does not count as a box.
Loose — 0.60
Assumes real loss to brackets, an awkward corner, or boxes stacked with a hand-gap left on purpose. Use this for a closet you have not measured carefully or one with visible obstructions.
Standard — 0.75
A reasonable default for a plain rectangular shelf or closet with no major obstructions. Most of our callers land here.
Tight — 0.85
Assumes a careful, deliberate stack with boxes chosen specifically to fit the space edge to edge. Rarely realistic for a first pass.
Where the box sizes come from
22 litres matches the Stackable Lidded Storage Boxes, Kraft, in the catalog, and 19 litres matches one bin from the Linen Storage Bins, Set of 2. Enter a custom figure for anything else you already own; the calculator does not need to know its source to do the division.