over the course of my studies of the lore through halowiki, halopedia, waypoint, and the games that I have played. I have yet to find just how long a forerunner life span is
could someone please tell me?
I may be wrong, but I believe I heard somewhere that a Forerunner life span is thousands of years. This is implied in the Halo 4 terminal videos.
I don’t think there is a set limit, their suits allow them to live for a long time and in some cases a Cryptum can extend that lifespan.
The maximum is vague, but we know for certain that they can live for over 12,000 years. We also know that Forerunners dying was a rare occurrence and mostly happened in combat or by accident, which suggests dying of old age really wasn’t a thing for them. This is, of course, thanks to insanely advanced medical science and not indicative of their natural lifespans.