The CRB says that when a character reaches venerable the GM should secretly roll their maximum age to determine when they will die of old age.
How?
How many die do you roll? Does it differ by race? The book lists minimum and maximum "starting" ages, but are their similar such things for maximum old age?
Page 169 of the Core Rulebook deals with this. An example is for humans, whose maximum age is 70+2d20 years.
Thanks. That provided enough new text for my google search, and I was able to find this:
http://www.d20pfsrd.com/alignment-description/description
I had been looking for a dwarf's max age, and according to the linked page, it's 250+2d100 years old.