Bilbo Baggins is 50 years old at the start of J.R.R. Tolkien’s The Hobbit.
Bilbo’s fiftieth birthday is an important point in the story’s chronology. Gandalf arrives at Bag End and draws Bilbo into Thorin Oakenshield’s quest to reclaim the Lonely Mountain from Smaug. Bilbo is presented as respectable, comfortable, and initially unadventurous, making his decision to leave home a major change in his life.
The number is easy to confuse with other ages in Tolkien’s legendarium. Bilbo later reaches the remarkable age of 111 and celebrates his eleventy-first birthday in The Fellowship of the Ring. Frodo is 33 when he comes of age, and Bilbo gives him the Ring before leaving the Shire.
Bilbo’s age also reflects Tolkien’s use of hobbit chronology. Hobbits come of age at 33, so a 50-year-old Bilbo is an established adult, not a young hobbit beginning ordinary life.