Before you signup for stackry you can see various shipping options and most of them are calculated by weight. Once you signup and get your parcels you get option with dimensional weight or whichever is higher, means suits stackry better. Even though there is avaiable service (usps) they wont offer to customer because it is cheaper. Also they charging bad address fee. I am not guilty because ebay seller had mistake in shipping address. Classic rip off service which I will not use anymore.