how old is sheldon in big bang theory

Sheldon Cooper in The Big Bang Theory is born on February 26, 1980. At the start of the series in 2007, he is 27 years old. Over the course of the show, which runs for 12 seasons, Sheldon ages accordingly, ending the series at 39 years old. He is a prodigy who graduated high school at 11, college at 14, and earned his PhD at 16. By the end of the series, he has matured socially, married Amy Farrah Fowler, and won a Nobel Prize in Physics at age 39