My understanding is that the "weight" field in products does not actually "mean" anything. If you want it to mean pounds, then be consistent . . . if you want it to mean "kilograms", then again, be consistent.
That said, I was testing my Fedex that I just setup, and it seems the rates are absurdly high. That made me wonder how Fedex is calculating the rate? Presumably it uses the "weight" field . . . what about dimensions? How (if at all) does it calculate that info?
Just trying to figure it out to see if this will suffice or if I will need to get an extension.
Best Answer
FedEx does use the weight field for calculations.
It does not take into account dimensions, there is no support for this in standard magento.
Weight is hardcoded to lbs, the FedEx implementation is pretty much US specific.
The implementation of FedEx does not take into account various factors that are important to get accurate shipping rates, if you need more accuracy you need an extension or to write an implementation yourself.
For many people tho the FedEx in magento does suffice. The dimensional part only comes into play if you have items that are dimensionally large. If you speak with your FedEx rep (or UPS if you are with them) they will be able to advise.