A user on Reddit compiled a complete list of all the current Overwatch heroes in-game and pinpointed their exact age and birth year.
The post reads, "The games is widely accepted to take place during 2076 so that is the year that I will use to make these calculations. I took the ages from the Wiki and subtracted them from the current year to get their birth year."
Roadhog and Moira, both at age 48 are in the middle of the Overwatch pack (looking at it from 1-100).
Looking through the list, it's pretty fascinating seeing the variety of ages being spread out. Some notable ones are Reaper, who is 58 years old, with the birth year is 2018! Reinhardt is the oldest at 61 years old.
One other interesting age is in regards to Zenyatta, who is technically 20 years old. That's only one year older than D.Va, who is age 19. Based on how Zenyatta composes himself, it seems like he would be much older. Even Junkrat is listed as 25 years old, which is not the first number that pops into mind when looking at him.
Lore for the Overwatch universe is an essential part of what makes the game engaging and fun. Looking for the specific timelines and happenings for each individual hero can bring a treasure trove of content. Since the list of heroes is so expansive, this brings a huge age range across the board.