According to The History of Middle-earth, Elrond was born during the First Age, in the year 532. The Hobbit takes place in 2941 of the Third Age, and The Lord of the Rings begins 60 years later. The First Age lasted 587 years, and the Second Age 3441 years. This means Elrond is roughly 6437 during The Hobbit and 6497 in The Lord of the Rings. And yet he doesn’t look a day over 3000.
Elrond’s advanced years afford him a position of respect and seniority, and the Lord of Rivendell is rightly considered a rich source of knowledge, wisdom and history. However, Elrond certainly isn’t the oldest elf in The Lord of the Rings, with Cirdan the Shipwright briefly appearing in The Return of the King.
Born even before the First Age, Cirdan is well over 10,000 years old, making Elrond look positively middle-aged in comparison. At the end of The Lord of the Rings, Elrond accompanies Gandalf and Frodo to the Undying Lands, his ancestral home. There, it’s natural to assume that Elrond went on to live for eternity across the sea.
When it comes to the elves of Middle-earth, Tolkien usually remains vague regarding years of birth. The exact age of Legolas, for example, is ambiguous, leaving fans to guess his approximate year of birth based on hints within the text. Elrond will reportedly return in the forthcoming Amazon Lord of the Rings series set during the Second Age, which should offer a deeper insight into the elf’s (relatively) younger years.