How to use the pallet rack positions calculator
- Enter the number of pallets you need to store.
- Enter the beam levels in a bay and the pallets that fit on each level.
- Enter the usable share of positions, which allows for empty slots and mixed sizes.
- Add the bay width, depth and aisle width to see the floor area.
Formula
Positions per bay = beam levels x pallets per level
Bays needed = pallets / (positions per bay x usable share), rounded up
Rack footprint = bays x bay width x bay depth
Floor area = rack footprint + bays x bay width x aisle width / 2
The aisle is counted half for each bay because one aisle usually serves two rows of racks.
300 pallets in racks three levels high
A bay with 3 levels and 2 pallets on each level has 6 positions. At 85% usable that is 5.10 positions, so 300 pallets need 300 / 5.10 = 58.8, rounded up to 59 bays. The 59 bays hold 354 positions in total.
With a bay 9 feet wide, 4 feet deep and a 12 foot aisle, the racks take 59 x 9 x 4 = 2,124 square feet and the shared aisle adds 3,186, for 5,310 square feet. Going to four levels gives 8 positions per bay and needs only 45 bays.
Why the usable share matters
A warehouse never fills every position. Pallets come and go, a position may hold a pallet that is too tall for the beam below it, and some positions are kept free so that stock can be moved. A usable share of 80% to 90% is common in planning, and it is your own call. Using 100% gives the minimum, which only works for a rack that is filled once and then left alone.
The number of bays is always rounded up, because a partly used bay still takes a whole bay of floor.
Planning the rest of the space
The floor area is a first estimate. It leaves out dock doors, loading areas, columns, fire lanes and offices. Heights, beam load limits and clearances depend on the rack and the building, so check them with the rack supplier. To plan how pallets are loaded see the Boxes per Pallet Calculator. The Inventory Turnover Calculator shows how fast the stock moves, the Days of Supply and Stockout Date Calculator shows how long it lasts, and the Stock Count Variance Calculator checks counts against records.
Assumptions and limits
- All pallets are the same size and fit every position.
- Every bay has the same number of levels and positions.
- The figures shown are examples. Use your own rack and pallet dimensions.
- Dimensions are in feet. Use the same unit for width, depth and aisle.
Frequently asked questions
What is a good usable share?
It depends on how much stock moves. A busy picking area keeps more positions free than a long-term store, so choose a figure that matches your operation.
Does the tool count the top level?
Yes. The levels you enter include every level that holds pallets, including one at floor height if the bay has it.
Why is the aisle halved?
An aisle between two rows serves both, so each bay is charged half of it. Use a larger aisle width if a row has its own aisle.
Can I use meters?
The area is labeled in square feet, but the arithmetic works in any unit as long as all three dimensions use the same one.