Traditional panettone size & volume?
For big (standard) panettoni typical values are:


Mould diameter of 17 cm (6.7 in).
Mould height of 11~13 cm (4.3~5.1 in).
Dough weight about 800 gr (1.7 lb).

Albeit those values are not defined in the Italian "standard", nor in the howto. You can also find wider and lower moulds for the same dough sizes (or upt to 1 kg / 2.2 lb). 

You can find those measures in most webs in italian. Also, if you buy an already made panettone it will quite probably have those or very similar measures.
In general, you can use the formula:


  Dough weight (gr) = 1,45 x Mould volume (cm3)


Formula calculated empirically. You can check some values in this italian forum.


When you pour the dough in the mould it will only be filled up to ¼ or ⅓. It needs to rise a lot: above the upper part of the mould. 

Here you have a Youtube video on making a homemade mould.
And this page shows you how to do the mould yourself. It's in Spanish, but you can translate it automatically.



Sidenote: Orthodox stress they should be done with lievito naturale (sourdough), not yeasts. Non orthodox italian standard accept only up to 0.01% of yeast.