How old is Bane?
1/18/78: roughly the date of Bruce Wayne's birth
1977-78: roughly the events of Ras' pregnant wife being put in the pit and the eventual birth of Talia
1984-88: around the time when Talia's mother was killed, Talia's climb out of the well, and the return assault from Ra's Al Ghul on those in the well who mauled the prisoner who saved Talia, the start of Bane.
This says Talia was between 6-10 years old, roughly 8.
1986-1987: roughly the events of Bruce falling into the well, and the eventual deaths of his parents at the hands of Joe Chill, who was apprehended by police and incarcerated.
This leaves Bruce at roughly age 8.
1986-2008: Sometime after Talia and Ra's rescue from the pit of what would become Bane, and before Ras took on Bruce as a student, Bane trained under Ras for some amount of time and was excommunicated for being a monster Ras' could not control or look upon, and Talia chose to go with him.
2000-2001: 14 years later, Bruce returns home from college to witness the hearing of Joe Chill due to his early release from prison in regards to incriminating information that was shared inside with former prisoner and mob boss, Carmine Falcone. Bruce's attempt to murder Chill is foiled at the last second when he is shot by one of Falcone's people. Bruce confronts Falcone and is easily subdued by his men, but Falcone's ego and insults inadvertently inspires Bruce to become Batman when he leaves Gotham to understand the criminal element and travel the world.
2001-2008: Bruce travels the world, masquerades as a criminal, learns crude ways of fighting and gets caught and thrown in jail during a heist. There he meets Ra's Al Ghul, who offers him a path, to train with the League of Shadows. The rest of Batman Begins plays out. Bruce is to be revealed to be 30 years old at his birthday party toward the final 30 minutes of the film.
2008-2016: Talia finds out at some point about Bruce's betrayal to the League and the death of her father at his hands. She and Bane formulate a very long con on Bruce as well as Batman, as well as fulfilling her father's plans for destroying Gotham.
07/18/08: 6 months after the events at the end of Batman Begins, the events of The Dark Knight take place, establishing a definitive year of when the events actually take place. Proof is on the security photo Gordon shows Batman of the Joker robbing the bank at the start of the movie. Bruce is still 30.
7-11/16: Bruce has retired for roughly 8 years as Batman due to the lie he and Gordon made up about Dent and the circumstances surrounding his death and the string of murders he committed; Batman is wanted for murder while Harvey Dent is martyred as the city's real hero. Bane and Talia enact their plan on Bruce. Eventually, Bruce is defeated by Bane and placed in the well for around 3 months before his escape. When he returns to Gotham for his rematch with Bane, it is snowing in Gotham which places the month around mid October to November.
Bruce is 38 years old.
Talia, at the time if her death, was 37-38 like Bruce.
Bane must have been at least 18-25 like Bruce was when Ras' rescued him from prison, which is what Ras' did for Bruce as well. Both also became members and former members of the League of Shadows. Bruce and Talia also lost one or both parents as a child; Talia only knowing one parent at a time but never together.
So Bane, say around 22, got messed up protecting 8 year old Talia al Ghul in 1986-1987. If the movie takes place in 2016 (as proved in the timeline), that's 30 years later, which means:
Bane has to be between 50-55.
CASE CLOSED.