Keep product dimensions, individual packed dimensions and shipping-carton dimensions in separate fields. They describe three different objects. Using one figure for all three makes gift-box design, storage and delivery estimates harder to check.
Measure the product in its agreed pose
A layered-scoops ice cream cone needs enough information to describe its full outline, not only the cone section. Show the measurement points and note any projecting feature. A catalogue photograph cannot establish scale without a measurement reference.
Add the actual retail packing
A bag, insert or box changes the packed outline. Request the dimensions of the proposed finished pack, including the arrangement of the product inside it. Do not assume a box can be specified by adding an arbitrary margin to one product measurement.
When more than one character shares a package, check the complete arrangement. The sum of individual widths is not a substitute for a packing test.
Obtain carton data from the packing plan
Ask for units per carton, the carton identifier and confirmed outside dimensions. Keep weight information in its own fields. If the pack arrangement changes, the earlier carton estimate may need revising.
Use a consistent length, width and height order, and state the unit. A spreadsheet containing mixed centimetres and millimetres can look plausible while being difficult to use correctly.
Can catalogue size be used for a delivery estimate?
It can start a discussion, but a useful shipment estimate needs the proposed packed quantities and carton information. Label preliminary figures as estimates and replace them when the actual plan is confirmed.
The packaging planning guide explains the decisions to settle before the packing dimensions become final.