Pallet load capacity is the maximum weight a pallet can safely support.
Detailed Definition
Pallet load capacity is the weight a pallet can safely carry under a stated support condition. It is usually given separately for static loads, when the loaded pallet sits on a flat floor, sometimes with other loads stacked on it; dynamic loads, when it is moved by forklift or pallet jack; and racked loads, when it spans an open rack. Static capacity is generally highest and racked lowest. Capacity depends on design, species and grade, component sizes, fasteners and how the load is spread. See static compression.
How capacity is determined
Capacity ratings come from engineering analysis, such as the Pallet Design System, or from laboratory testing under methods like ASTM D1185 and ISO 8611. Tests load the pallet in defined support conditions and measure failure loads and deflection, and a safety factor or deflection limit is then applied to get a usable rating. A rating only means something when it states the support condition, the load type and the criteria behind it.
Why the same pallet has several ratings
On the floor, the bottom deck spreads the load and the pallet can carry a lot. On forks, it is supported only where the tines are. In rack, it spans between beams, so stringers or deck boards bend, and direction matters: a pallet racked across its length behaves differently from one racked across its width. Load type matters too. A uniform load of cases is easier on a pallet than a concentrated load such as a machine, or a bag that sags between boards.
What to tell a supplier
- Load weight and how it sits on the deck.
- Whether it is stored on the floor, stacked, racked or all three.
- Rack beam spacing and which way the pallet spans.
- The handling equipment used.
Authoritative Sources
- ASTM International (ASTM): the global standards body that publishes ASTM D1185 (Standard Test Methods for Pallets and Related Structures Employed in Materials Handling and Shipping).
- National Wooden Pallet & Container Association (NWPCA): the US trade association representing wood pallet manufacturers, recyclers, and component producers, founded in 1947.
Related Glossary Terms
Frequently Asked Questions
What is the difference between static, dynamic and racked capacity?
Static capacity is the load a pallet can hold while resting on a flat, solid surface, which may include other loads stacked on top. Dynamic capacity is the load it can carry while being lifted and moved by a forklift or pallet jack. Racked capacity is the load it can carry while spanning an open rack bay, supported only at its edges. For most pallets static is the highest of the three and racked the lowest.
Can I use a pallet's static rating for rack storage?
No. A static rating assumes full support underneath. In rack, the pallet spans an open space between beams and has to resist bending, so the safe load is usually much lower. Using a static number for a racked load risks a pallet breaking in the rack. Ask for a racked rating for your beam spacing and the direction the pallet spans, or use pallet supports or decking if the rack design allows.