KubovaMixed-SKU Container Loading: The Problem Single-SKU Calculators Can’t Solve
By Kubova Team
Real orders are rarely one product. They’re a mix of cartons — and how you combine them decides whether they ship in one container or three. Single-SKU calculators can’t see this, which is why they so often over-book space. Here’s the difference, measured.
One order, two ways to load it
We took a three-SKU order and packed it two ways with the same engine:
Each SKU in its own container — every one of them only partly full.
The three carton sizes interlock — one full 40 HC instead of three.
Order: 220 × 60×40×30 cm, 160 × 50×50×50 cm, 320 × 40×30×20 cm. Kubova engine, measured 2026-06-08.
Why mixing wins
A single carton size leaves a predictable pattern of gaps — the strips and partial layers it can’t fill. Different carton sizes fill each other’s gaps: the small 40×30×20 cartons drop into the spaces the bulky 50 cm cubes leave behind. That’s why, in our fill-rate benchmarks, the mixed profile reached the highest volume use (~93%) — higher than any single carton on its own.
When not to mix
Mixing is a geometry advantage, but it never overrides handling and compliance:
- Fragility & stacking. Don’t put crushable cartons under heavy ones just to close a gap.
- Segregation. Dangerous-goods incompatibilities, contamination or temperature concerns can require keeping products apart.
- Lot / customs separation. Some shipments must keep lots or consignees physically separate.
Within those rules, mix as much as the geometry allows.
What you need to plan a mixed load
- Outer carton L×W×H, unit weight and quantity for each SKU.
- Any stacking or no-stack rules per SKU.
- A tool that places all SKUs together in one plan — not one at a time.
Pack all your SKUs in one plan
Add every carton and see whether they consolidate into fewer containers. Free to start.
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Frequently asked questions
What is mixed-SKU container loading?
It’s planning a container load that contains several different products (SKUs) together, placing them so the smaller cartons fill the gaps the larger ones leave. It’s how real orders ship — and it’s exactly what single-product calculators cannot model.
Does mixing SKUs really save containers?
It can save a lot. In our engine test, a three-SKU order packed together fit into one 40 HC; loaded one SKU per container it needed three containers. Mixing turned three half-empty containers into one full one. The savings depend on the cargo, but the direction is consistent.
Why can’t a single-SKU calculator handle this?
A single-SKU tool computes each product’s fit in isolation, so it never sees that product B’s cartons could drop into the gaps product A leaves. It will tell you each SKU needs its own container and miss the consolidation entirely.
When should you NOT mix SKUs?
When products must be segregated — fragile items under heavy ones, dangerous-goods incompatibilities, temperature or contamination concerns, or customer/customs requirements to keep lots separate. Mixing is a geometry win, but handling and compliance rules come first.
Who: Written and reviewed by the Kubova team, who build and operate the packing engine described here.
How: Drafted with AI assistance for research and structure; the technical claims, examples and product details are owned and verified by the team.
Why: To help logistics and engineering teams decide whether to let an AI agent plan their loads — not to chase a keyword. Published 2026-06-08.