TI is cases per layer. HI is layers per pallet. For identical, full layers, multiply them to get the total case count. Neither number tells the operator where the cases go, so a production instruction also needs a pattern diagram.
This distinction is reflected in the GS1 Global Data Model, which records units per layer and numbers of layers as separate attributes. Use the terms expected by your customer or warehouse, and identify what “unit” means in that exchange.
1. What TI and HI Mean
A build labeled TI 16, HI 6 contains 96 cases when all six layers are full. If each case contains 12 sales units, that is 1,152 sales units. Do not report those sales units as the TI: TI in this example counts cases.
The notation does not specify case orientation, layer offsets, overhang, pallet construction or containment. Two builds can have the same TI and HI while behaving differently in handling.
Try it with your dimensions
Plan the count and the arrangement
Compare case layouts and layer counts, then inspect the complete pallet build.
Open calculator2. How TI Is Calculated
For upright rectangular cases in a simple grid:
TI = floor(pallet length ÷ case length) × floor(pallet width ÷ case width).
Use packed outside dimensions and common units. Repeat after swapping case length and width.
A 12 × 10 in footprint on a 48 × 40 in pallet gives:
- 12 in along 48 in: 4 × 4 = 16.
- 10 in along 48 in: 4 × 3 = 12.
Five 10-inch cases cannot fit along 48 inches with zero overhang. Do not write an alternative 5 × 3 = 15 layer for this case size unless a different, explicitly drawn arrangement actually fits.
Mixed patterns can outperform a simple grid, but every case position needs to fit. A larger theoretical count is not permission to compress the case dimensions or overlook bulge.
3. How HI Is Calculated
Calculate independent height and weight ceilings.
HI by height = floor((total height limit − pallet height − allowances) ÷ case height).
For a gross loaded-unit mass limit and constant TI:
HI by weight = floor((gross limit − pallet tare − accessories) ÷ (TI × case mass)).
If a supplier gives a payload rating instead, use the supported payload against that value. Keep any gross handling limit as a separate check.
The smaller of the height and weight ceilings is only the initial candidate HI. Compression, load support, receiver rules and transport qualification can reduce it further.
4. Worked Example: A Weight-Limited Build
Assume 12 × 10 × 8 in cases at 25 lb each, a 48 × 40 in pallet with a 5 in height and 40 lb tare, no accessories, and route limits of 102 in total height and 2,500 lb gross. These are illustrative limits, not a universal GMA specification.
| Quantity | Calculation | Result |
|---|---|---|
| TI | 4 × 4 | 16 |
| Height-limited HI | floor(97 ÷ 8) | 12 |
| Weight-limited HI | floor(2460 ÷ (16 × 25)) | 6 |
| Cases | 16 × 6 | 96 |
| Gross weight | 96 × 25 + 40 | 2,440 lb |
| Loaded height | 6 × 8 + 5 | 53 in |
Scroll to compare all columns.
Write TI 16, HI 6, 96 cases. The weight budget could numerically accommodate 98 cases, but adding two cases creates a partial seventh layer that needs a separate instruction and evaluation.
For another arithmetic check, 24 cases per layer at 40 lb each create a 960 lb layer. With the same 2,460 lb case-weight budget, only two full layers fit: 48 cases, or 1,960 lb gross including the pallet.
5. Different Counts on Different Layers
When layer counts vary, total them explicitly:
Total cases = sum of the case count on each layer.
For example, if an approved drawing has five layers of 16 cases and five layers of 15 cases, the total is 5 × 16 + 5 × 15 = 155. This is a counting example, not a claim that those two patterns fit any particular case or pallet.
A partial top layer should identify its case positions and restraint. “TI 16, HI 7” would be misleading for six full layers plus two cases. Write the full-layer quantity and the two-case top layer separately.
6. Reading a Pallet Pattern Sheet
A useful instruction includes:
- Case identity, gross weight, outside dimensions and allowed orientations.
- Pallet identity, dimensions, tare, condition and applicable working-load limits.
- Diagram and count for each distinct layer, with their sequence.
- Total cases, loaded height and gross weight.
- Overhang or setback policy and dimensional tolerances.
- Wrap, straps, edge boards, top protection and layer sheets as applicable.
- The receiving specification and approved build revision.
A layer count is not a substitute for physical height. A five-layer stack of tall cases can be higher than a twelve-layer stack of shallow trays.
7. TI / HI and Box Compression Strength
In a simplified, equally loaded column stack, each bottom case carries approximately:
Load from cases above = (HI − 1) × case weight.
At HI 6 and 25 lbf per case, that is 125 lbf per bottom case. Interlocked layers, rigid contents, uneven support and stacked pallets change the load path. Use Box Strength to examine the relevant assumptions; do not apply a generic “SF 3” or “SF 4” without defining its basis.
8. TI / HI and Load Stability
HI alone cannot establish a safe stability category. Physical height, mass distribution, footprint, friction, containment and the handling environment all matter. Six tall layers are not automatically safer than eleven short ones.
Pallet Load Stability provides a geometric tipping screen under stated assumptions. It does not validate film containment or dynamic transit behavior. Where the build changes, review the distribution test plan against the actual shipping unit.
Use the boxes-per-pallet guide for complete imperial and metric calculations, then document the selected arrangement in the Pallet Calculator.