People of the epic · Mahabharata questions
How old was Krishna in the Mahabharata war?
The epic never gives his age. Traditional reckoning has Krishna living 125 years and leaving the world 36 years after the war, which would make him about 89 at Kurukshetra. That figure comes from Puranic chronology, not from the Mahabharata itself.
The Mahabharata gives no age for anyone, Krishna included. It says he is older than the Pandavas, that Kunti is his father sister so he is their cousin, that he has grown sons and grandsons by the time of the war, and that his hair is greying. That is the whole of the textual evidence.
The traditional figure comes from the Puranas and from the chronology built around the yugas. There, Krishna lives for 125 years and some months, and the Kali Yuga begins at the moment he leaves the world. The Mausala Parva states the interval directly: Gandhari curses him on the battlefield that his clan will destroy itself, and the destruction comes thirty-six years later, when Krishna is killed by a hunter arrow at Prabhasa and Dwaraka is taken by the sea. Subtracting thirty-six from a hundred and twenty-five gives about eighty-nine at the time of the war, which is the number usually quoted.
Two cautions. First, the hundred and twenty-five years is a devotional and Puranic tradition, not a statement in the epic. Second, the internal chronology does not fit an ordinary human life easily: Krishna kills Kamsa as a youth, is already a statesman when the Pandavas are young men, survives their thirteen-year exile, drives a chariot for eighteen days of war, and lives another thirty-six years after it. The epic is not tracking a biography.
What the text does keep consistent is the thirty-six years after the war. That span is load-bearing. It gives Yudhishthira his reign, it gives Parikshit time to be born and grow, and it sets the clock on Gandhari curse.