Learn how cartonization works and if it's right for you.

Zonos uses cartonization to provide a shipping quote based on shipping box size rather than your item weights or item dimensions. Using a list of your shipping box sizes, we will sort the items in the checkout (using your item dimensions) into the smallest shipping box possible. Our system will then compare the dimensional weight of your shipping box(es) with the physical weight of your items, and quote shipping costs based on the greater of the two (the same way that the carriers will rate).

When to use cartonization 

Cartonization is meant to be used when dimensional weight influences your shipping cost and your item dimensions do not give the full picture of how much space the order will take up when shipped.

Here are some examples of when the dimensions of your items may not provide a complete picture:

  • The dimensions of your shipping box sizes are much larger than the dimensions of your items.
  • Some of your items ship in multiple boxes.
    • Ex: a punching bag that always ships in two boxes - one with the punching bag and one with the platform base (both included in the same listing).
  • Some of your items always ship alone, meaning that when that item is in a cart with another item, they cannot fit in the same box.

If your shipping box dimensions do not make much of a difference in shipping cost, it may not be worth the effort of setting up cartonization. We can still calculate shipping costs based on the dimensional weight of your items without setting up cartonization.

How to set up cartonization 

To use cartonization, you must do two things:

  1. Provide Zonos with your product dimensions. You can do this one of two ways:

    1. Input all of your item dimensions into Catalog. Learn how to add item dimensions to Catalog.
    2. Add your item dimensions to your product listings in your ecommerce platform. This option can only be used if your ecommerce platform passes dimensions to Zonos. Check "Product info by platform" to see if your platform will pass item dimensions to Zonos.
  2. Send a spreadsheet of your shipping box dimensions to Zonos using our cartonization template. If you are going through onboarding, send your completed sheet to your Project Manager. If you are already live with Zonos, send it to our support team at

Special circumstances

Zonos' cartonization solution can also handle special shipping circumstances, including those involving multi-box shipments or items that are typically ship alone.

Items shipped in multiple boxes
Items shipped alone

To set up items that ship in multiple boxes:

  1. Input all of your item dimensions into Catalog.
  2. Complete the spreadsheet Items that Ship in Multiple Packages.
  3. Send the completed sheet to your Project Manager (if you are going through onboarding) or to if you are already live with Zonos.

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