Macro to "accurately" calculate average item level?

[jakobud]

It seems like every macro that I try that is supposed to calculate my average item level is not accurate. That is, it does not match up with what the default UI's dungeon finder is telling me. For example this one:

/run local t,c,u,k=0,0,UnitExists("target")and"target"or"player"for i=1,18 do k=GetInventoryItemLink(u,i)if i~=4 and k then t=t+select(4,GetItemInfo(k))c=c+1 end end c=c>0 and print(t/c)

When the dungeon finder was telling me my average item level was 160, this macro was saying it was something like 139.3949. Why is it so far off? Are there any macro's that do it correctly?

Also, how is the average item level officially calculated? Does it use item's in your bag? Does it use items in your bank? I noticed that when I de-equipped an item, like a chestpiece and left that slot blank, the average item level did not change, that makes me think it uses what is in your bag too... Anyone have any clue? I don't see any equations on wowwiki for this.

[Bruin]

it uses your best armor slot items (so everything except Shirt and Tabard), regardless of on character/bag space/ or bank. It does not count items such as a Tabard since that has an item level of 1. If I recall correctly it also has to be a wearable item by you.

I am not fully sure, but I *believe* a character wearing Heirloom items (which are considered to be Level 1) will also show a lower average than a similarly leveled character. I haven't checked the numbers on my alts to say that for certain.

[daphoosa]

I believe that the blizz average item level only looks at your 5(?) best items, not all of your items.

[Verdris]

Officially, average item level is calculated from the best item you own for that slot, not what you have equipped - I'm not sure if this extends to the bank. Furthermore, before November 23rd, heirlooms were counted as 187. Now, they're 1. This change made my Shaman unable to queue for heroics (even after getting several heroic achieves via the dungeon finder the week before) until I bought items from the AH to fix the problem. I didn't equip them, I'm just going to auction them back once I no longer need them.