This is NOT an “accepted solution” by any means. To tell us to go get an app to do something so BASIC is RIDICULOUS.
ICYMI - I switched to Shopify from Go Daddy’s Quick Shopping Cart that I used since 2006. THEIR shipping calculator had taken into account the SIZE and weight of the wrapped items in order for the calculator to choose/pack the RIGHT BOX and quote the RIGHT SHIPPING COST.
Since 2006 I might add!!!
To not be able to do this within the Shopify shipping calculator tells me they own Boxify and want to nickle-and-dime us for more money.
Why else would they do NOT do this?
To not calculate the SIZE of an item for the postage costs is unbelievably ignorant of the way the post office and the carriers work.