Amazon FBA Pallet Calculator (Ti-Hi & Height Check)

1. Standard Pallet Specifications & Wood Quality Rules

Amazon operates the world's most automated fulfillment center network. When shipping Less-Than-Truckload (LTL) or Full-Truckload (FTL) freight to Amazon fulfillment centers (FCs) across North America, compliance begins with the physical wooden pallet foundation itself. Amazon US fulfillment centers exclusively mandate standard 40 × 48 inch Grocery Manufacturers Association (GMA) Grade B or higher wooden pallets.

To prevent dock conveyor snags, automatic high-bay retrieval jams, and forklift tines failures, pallets tendered to Amazon must strictly meet the following structural guidelines:

• Four-Way Forklift Access: The pallet must have cut-out stringers or block construction that permits entry from all four directions by standard hydraulic pallet jacks and counterbalance forklifts.
• GMA Grade B (Number 2) or Better: Pallets may have repair plates or companion stringers, but stringers must not have cracked, severed, or splintered structural wood. Missing deck boards are grounds for immediate trailer rejection at the security guard shack.
• Prohibited Materials: Do not use pallets made of weak composite materials such as pressed cardboard, particleboard, or plastic unless prior written authorization has been granted for specific specialized ASIN categories.
• International ISPM-15 Compliance: All wood packaging materials imported into the United States or cross-border between the US, Canada, and Mexico must display an official IPPC stamp verifying heat treatment (HT) or methyl bromide fumigation.

2. Amazon Maximum Height and Gross Weight Thresholds

A frequent cause of costly chargebacks and inbound performance defects is exceeding maximum height or weight ceilings. Amazon measures height from the warehouse concrete dock floor to the absolute highest point of the upper carton layer:

*Note: If an individual master carton exceeds 50.0 lbs, it must be marked with large, prominent "Team Lift" warning labels on all four vertical sides and the top panel. Master cartons exceeding 100.0 lbs require "Mechanical Lift" labels.

3. Understanding Ti-Hi Math for Maximum Pallet Density

In logistics engineering, Ti-Hi (Tier and High) is the standard formula used to compute carton layout geometry:

• Ti (Tier): The number of master cartons that fit onto a single horizontal layer of the pallet deck.
• Hi (High): The number of tiers or layers stacked vertically atop one another.

The product of these two numbers defines the total volumetric capacity of the pallet: Total Cartons = Ti × Hi. For instance, a Ti of 10 cartons layered 6 tiers high yields 60 cartons on the pallet.

Column Stacking vs. Interlocking (Pinwheel) Stacking

When packing master cartons, warehouse dock teams generally utilize two stacking architectures:

1. Column Stacking: Boxes are stacked directly on top of each other with their vertical corners aligned across all tiers. Because boxes derive most of their vertical compression strength from their corners, column stacking typically preserves maximum box strength. However, column-stacked pallets require tight stretch wrapping to avoid swaying or separating during transit.

2. Interlocking (Pinwheel) Stacking: Carton orientations are alternated between layers, overlapping joints like brickwork. This significantly improves load stability and reduces shifting on the trailer floor. However, because corners do not align directly over lower corners, interlocking can reduce the effective vertical compression resistance of the lower boxes, so ensure your corrugate meets appropriate Edge Crush Test (ECT) ratings.

4. Stretch Wrapping, Strapping, and Overhang Rules

Amazon enforces a zero-tolerance policy on carton overhang. Cartons must not extend beyond the perimeter edges of the wooden pallet deck by any margin (0.0 in / 0.0 cm). Overhanging cartons risk puncture and crush damage when pallets are positioned adjacent to one another inside trailers.

• Clear Stretch Film Only: Wrap all pallets in clear plastic stretch wrap. Amazon prohibits opaque, black, or colored stretch film because receiving teams must inspect carton barcodes and FBA box labels without slicing open wrapping.
• Secure the Pallet Base: Stretch wrap must wrap securely around the top deck boards and stringers of the wooden pallet base to anchor the cargo directly to the wood foundation and prevent in-transit load shifting.
• Flat Top Tier: The top tier of the pallet must be level and stable. Pyramid stacking (where top boxes taper off into a peak) is prohibited because it prevents safe double-stacking in carrier trailers where permitted.

5. Amazon Inbound Receiving Guidelines & Shipment Compliance

Failure to comply with Amazon's inbound packaging policies triggers Inbound Performance Alerts in Seller Central. Amazon may charge for manual re-work, carton re-labeling, or refuse delivery:

• Overweight & Labeling Rules: Master cartons must not exceed 50.0 lbs unless containing a single oversized unit. Cartons exceeding 50 lbs must be clearly labeled "Team Lift" on all sides and the top panel. Master cartons exceeding 100 lbs require "Mechanical Lift" labels.
• Unstable or Over-Height Pallets: If a pallet exceeds 72 inches or arrives leaning, crushed, or overhang-damaged, Amazon fulfillment centers may charge re-palletizing and manual restacking labor fees or reject the shipment outright, returning the trailer at your expense.
• Overhang Policy: Amazon enforces a strict 0-inch overhang tolerance. Even small overhangs risk carton puncture or rejection during automated cross-dock handling.