11/08/2026
Why Do Suppliers Always Give Inaccurate Volume and Weight Data?
Over the years working as a foreign trade SOHO, I've constantly run into this problem: the gross weight and volume figures provided by suppliers are often inaccurate, causing cargo that won't fit into the container, or total weight that exceeds the container's weight limit.
For example, the supplier quotes 0.08 CBM per carton, but when the goods actually arrive at the warehouse, it turns out to be 0.12 CBM. For 20 cartons, that's an extra 0.8 cubic meters out of nowhere, meaning not all the goods can be loaded into the container and some have to be left behind. Another case: the supplier quotes a gross weight of 20 kg per carton, but the warehouse scale shows 23 kg. Sometimes this pushes the entire container overweight, incurring extra trucking fees, and on a few occasions, the cargo almost couldn't even get on the vessel.
Why are supplier-provided figures always off? After all the pitfalls I've stumbled into over the years, I've boiled it down to four core reasons:
First, the factory's habit of "eyeballing" it is hard to break.
Many salespeople and production staff rely on experience: "This product is about 5 kilograms," "The carton is roughly this big." In their minds, "close enough" is fine. But when it comes to actual delivery, "close enough" becomes "way off." A 0.02 CBM discrepancy per carton, multiplied by hundreds of cartons, adds up to several cubic meters — enough to cover a round-trip flight to your customer's country.
Second, measurement tools and standards are not uniform.
I've seen factories use tape measures to measure carton sizes, without accounting for bulging edges; and old-fashioned platform scales with precision no better than 0.5 kg. Even more common: the factory quotes the "bare product" dimensions, but after packing, the outer cartons bulge, tape adds thickness, and pallet height isn't included. In reality, what ships is always the maximum outer carton dimensions — nothing less.
Third, there's a disconnect between workshop reality and theoretical specs.
The salesperson gives you carton dimensions based on "design values." But on the shop floor, inner boxes aren't placed flat, cartons deform after sealing, or pallet stacking patterns change — none of these details get fed back. The salesperson simply copies last shipment's data and sends it to you. When the goods arrive at the warehouse and measurements come out different, the supplier casually brushes it off: "Oh, we used new packaging for this batch."
Fourth, and most painfully — no one bears the cost of data inaccuracies.
The supplier's inaccurate figures don't cost them anything. Extra freight, rework, or penalties — none of that affects their bottom line. Without financial consequences, there's no real incentive to be precise.
That said, there are certainly some suppliers who are deeply experienced in foreign trade and take data accuracy seriously. And their businesses are thriving. Why? Because they treat carton measurements and weights as part of their quality management. Only those suppliers who take quality management — including data accuracy — seriously can maintain long-term customer loyalty and keep their clients coming back.