How old was Plato when he became a student of Socrates

Plato became a student of Socrates at the age of 20.

Plato became a student of Socrates when he was around 20 years old. Plato was born in 427 or 428 BCE, and Socrates was his teacher until Socrates' execution in 399 BCE. Therefore, Plato would have been in his early twenties at the start of his association with Socrates.