Reading a Carton Spec Sheet: The Four Numbers That Decide Your Freight

A carton specification is four numbers. Most order confirmations contain none of them, which is why freight quotes for the same goods can differ by 40%.

The four numbers

pieces_per_inner_box
inner_boxes_per_carton
carton_dimensions_cm   // L x W x H
carton_gross_weight_kg

From these you can derive everything that matters: total cartons, total volume, total volumetric weight, and the chargeable weight the carrier will actually use.

Why the average is the enemy

I have seen packing lists state "gross weight: 12 kg (approx.)" for a range where individual cartons run from 9 to 16 kg. That average is worse than no number, because it looks like data.

Volumetric weight is calculated per carton. If a carrier charges on the greater of actual and volumetric, the 16 kg carton and the 9 kg carton can end up on different chargeable bases, and the blended rate you were quoted quietly stops applying.

The mixed-carton problem

For an assortment, "pieces per carton" is often a capacity rather than a commitment. A carton rated for 200 pieces might take 160 if the mix skews large, because large shapes create voids that cannot be recovered.

This is not dishonesty, it is physics. But it means the carton count in your landed cost model is a range, not a point, unless you pin it down in writing.

What to ask for

Before the deposit, ask for the breakdown per SKU, not per order:

• pieces per inner box, per design
• inner boxes per outer carton, per design
• carton dimensions and gross weight, per design
• whether the assortment can be repacked to hit a fixed carton count

That last question is the one that separates a supplier who packs deliberately from one who packs whatever fits.

The cheap test

Ask for a photo of one packed carton, open and closed, before the balance payment. If the carton count in the photo matches the spec sheet, the spec sheet is real. If it does not, you have found the problem at the cheapest possible moment.

Carton-level detail for each format is described on the offerings page, and the pre-order checklist that catches most of this is on the sourcing checklist.

Four numbers. Ask for them in writing.

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Written by Zhao Jin, sales at Yiwu Jinji Trading Company (King Squishy), a Yiwu-based supplier of wholesale squishy and fidget toys working with partner workshops. [e-mail] · WhatsApp [phone].