Stackable pallets and stack height
How high a stack goes is the static rating divided by the weight of each loaded pallet above, less a margin the maker may set for stability.
The arithmetic
Take a stackable rated 10,000 lb static. If each loaded pallet above the bottom one weighs 2,500 lb, the bottom one can carry four above it, which makes a stack five high. At 3,300 lb per pallet it can carry three, a stack four high. This is a ceiling for a still stack on a flat floor, not a promise for a stack that moves or waits.
| Loaded pallet weight | Pallets above the bottom (10,000 lb static) | Stack height |
|---|---|---|
| 1,000 lb | 10 | 11 |
| 2,500 lb | 4 | 5 |
| 3,300 lb | 3 | 4 |
| 5,000 lb | 2 | 3 |
What limits a stack besides the rating
- Stability. A tall stack of narrow loads leans before it crushes. The footprint of the load, not the pallet, sets this.
- Time. Held weeks under load, plastic can bow where a day would not. The creep guide explains the effect.
- Temperature. A rating taken at room temperature says little about a cold store; see cold performance.
- The floor and the reach. A forklift needs mast height, and sprinkler heads need clearance. Ask the building, not just the pallet.
When to give up stacking
If the stack is high enough that the arithmetic needs a margin, rack it. A rackable pallet is rated for the beam span, and a rack carries each pallet by its own edges rather than through the ones below. The rackable hub shows the rating that decides it.
A stack worked out
Take a stackable rated 10,000 lb static. The bottom pallet carries the pallets above it, so with each loaded pallet weighing 1,594 lb it can hold 6 above, a stack of 7. With 5,636 lb per pallet it can hold 1 above. This is a ceiling on a flat floor for a still stack, not a promise for a stack that moves or waits.
| Loaded pallet, lb | Pallets above the bottom | Stack height | Load on the bottom pallet, lb |
|---|---|---|---|
| 1,594 | 6 | 7 | 9,564 |
| 2,101 | 4 | 5 | 8,404 |
| 2,608 | 3 | 4 | 7,824 |
| 3,115 | 3 | 4 | 9,345 |
| 3,622 | 2 | 3 | 7,244 |
| 4,629 | 2 | 3 | 9,258 |
| 5,636 | 1 | 2 | 5,636 |
Stack height in practice
Dock managers set stack limits by feel, and the feel is usually conservative. A good rule is to let the arithmetic on this page set the ceiling and let the dock set the working height below it. Stability, forklift reach and the sprinkler clearance usually bind before the pallet rating does.
Keep stacks on a flat, clean floor, align the pallets with one another, and wrap the load so it moves as one. A stack that leans loads one corner of the bottom pallet, and a corner load is not what the rating assumes. If a stack has begun to lean, unstack it.
Questions to put to the maker
- Does stretch wrap or a top frame change the stacking guidance?
- Does the stack rating assume a closed deck on the pallet above?
- What is the pallet's empty weight, so the load on the bottom pallet can be added up?
- Which deck pattern gives the best grip for the load, and what does it do to the rating?
- Is the dynamic rating printed next to the static one, and for which handling method?
- Is the rating the same on a slick floor, a conveyor and a rack?
- Does the pallet have a lip or a raised edge to hold the load in a stack?
- Is the static rating for a stack of the same pallets, or for one pallet on a flat floor?
From the dock
- Warehouse floors are rarely flat; a slight slope turns a safe stack into a tall lever.
- Weigh a sample loaded pallet before trusting any estimate; stacked weight grows faster than people expect.
- Forklift tines catch deck edges; closed decks with chamfered edges suffer less from rough entry.
- Plastic gets stiffer in the cold and softer in the heat, so the same stack behaves differently in two seasons.
- Creep is slow. A stack that looks fine on Monday may have sagged by the next month in a warm store.
- Slick film wrap and a smooth deck make a skating surface; a gripping deck pattern holds cartons still.
- Pallet jacks need clear entry on the bottom; feet and runners that block a wheel make a slow dock.
Words on this page
- Dynamic load
- The weight a pallet holds while it is moved by a forklift, pallet jack or conveyor. It is lower than static because motion adds shock.
- Creep
- Slow, permanent bending of plastic under a steady load. A pallet can hold a load for an hour and bow under it after a month.
- Closed deck
- A solid deck that keeps small items and torn bags from falling through and wipes clean on top.
- Open deck
- A deck with slots or a grid, which drains water, sheds dust and weighs less than a solid one.
- 4-way entry
- A pallet that forks or a pallet jack can enter from all four sides.
- Runner
- A continuous rail under a pallet. Runners lie flat across rack beams but stop pallets from nesting.
- Stretch wrap
- Elastic film wound around a loaded pallet to hold the load together.
- HDPE
- High-density polyethylene, a tough resin used in many plastic pallets, valued for strength against its weight.
Tell us the footprint and how many stacks you move.
We work out the empty trailer, then take the request for a load.