If you just add up the gear score of the armor pieces and divide by that many pieces, how do you factor in earrings, relics, and the like that don't have one listed?

Why would you want to calculate that? SWTOR does not have an Average Item Level at the moment, so there is no "official" way on how to weigh the different pieces.

 

If you are talking about the PvP bolster, they look at the individual slots and bolster each one to the same level. (http://www.swtor.com/community/showthread.php?p=7099225#edit7099225)

 

If you want to tell someone else what your gear is, it is usually fine to say something like "mostly 78, with 72 setbonus and Arkanian relics" since that contains much more information than some arbitrary number.

Edited March 29, 2014 by Jerba

The short answer to your question is you ignore the 5 slots with no rating and rely on the 9 that have ratings. The rating is on the armoring, hilt or barrel. For example I have a 4 piece underworld set and a 72 hilt all of the rest is Dread Forged. So: 5 x168 + 4 x 180 = 1560/ 9 gear score is 173.3

Why would you want to calculate that? SWTOR does not have an Average Item Level at the moment, so there is no "official" way on how to weigh the different pieces.

 

If you are talking about the PvP bolster, they look at the individual slots and bolster each one to the same level. (http://www.swtor.com/community/showthread.php?p=7099225#edit7099225)

 

If you want to tell someone else what your gear is, it is usually fine to say something like "mostly 78, with 72 setbonus and Arkanian relics" since that contains much more information than some arbitrary number.

 

this, basically, except also add if you are augmented or not. gearscore as a singular number was never particularly good idea to begin with as it never paints a full picture, and in SWTOR especially, for example set bonus arkanian (69) armorings are almost always better than non set oriconian (78) (almost because for some specs 4 pc set bonus can be situational...) a high end barrel/hilt will do more for your output as a dps/healer than any other piece of gear, etc etc.

 

(incidentally, for pvp, if you want to take full advantage of bolster - do NOT mix pvp and pve modifications, as any amount of expertise in a piece will result in no more additional expertise through bolster, putting you under cap. among other things)

The short answer to your question is you ignore the 5 slots with no rating and rely on the 9 that have ratings. The rating is on the armoring, hilt or barrel. For example I have a 4 piece underworld set and a 72 hilt all of the rest is Dread Forged. So: 5 x168 + 4 x 180 = 1560/ 9 gear score is 173.3

 

That explains the gist of it, but just counting the rated spots would give a incomplete picture. If I were to program a tool for calculating gear score I would use text matching on the last spots to attach a rating (ex: Verpine/Underworld = 168)