how much damage does a great axe do if it's huge
I cant seem to be able to find out what Damage dice it would be.
You want this FAQ.
4d6, by that chart.
(In general damage doubles per two size steps. So 2d6 (medium) becomes 4d6 (huge), and 1d12 ought to become 2d12, but it instead becomes 4d6 because that way they only need one table.)