ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
Dimensional weight is already in eBay's calculations because the retail rates match those of the carrier websites.
The numbers on the USPS website match those of eBay's calculator (there is no discount for ground packages). The package suffers from dimensional weight and oversize (longer than 22 inches). $85.20 for USPS Retail Ground.
Fedex Ground shows a public rate of $49.22, which matches eBay's calculator. My account shows a commercial rate of $40.88. eBay probably receives a deep discount.
UPS shows a billable (dimensional) weight of 61 pounds to zone 3 at a cost of $37.91, which is not a retail rate (not sure what that is). eBay shows a retail rate of $48.23. My account shows a commercial rate of $37.28. Again, eBay probably has a deeper discount.
If using calculated shipping, you might want to add a handling charge, just in case the package bulges a little.
@computer-girl wrote:... I am assuming what it is you are saying is that if the package bulges, it would change the dimensions.
If you are listing the item for sale, then, yes, I would add $5 just in case there is a backbill from the carrier (through your eBay account) for a dimensional increase or some other unknown increase. It would mitigate the extra charge somewhat. If you have enough profit in your item, then you could absorb any backbill.
If this is a post-sale shipment that has already been paid, then there is nothing to do but ship the item based on the best rates. We seem to see more "erroneous" backbilling from Fedex on the forums than from the other carriers (members suggest that two items might get weighed/measured as one while going through the scanners).
