Answer:
Vegeta's appearance appears younger than his actual age, because of his saiyan heritage. In the Dragonball Z Movie T.V. Special "Bardock, The Father of Goku" (wich is set 23 years before the start of Dragonball Z) Vegeta is at the age of 5 years old. At the time of his debut in Dragonball Z he is 28 years old ,and 29 years old at the time of his first encounter with Earth. After his death (at the hands of Frieza), and the arrival of his future son (Trunks) he is 31 years old. After his 3 years of training for the android threat and to become a super saiyan(which he succeeds) is 34 years old.
After a year, and training in the Hyperbolic Time Chamber (twice), he is 37 (chronologically he is 35). 7 years later during the events of the Majins, Vegeta is 44 years an old (chronologically he is 42). 10 years later, at the end of Dragonball Z, he is 54 years old (chronologically 52). At the start of Dragonball GT, Vegeta is 64 years old (chronologically 62), at the end of the series he is 65 (chronologically 63). Though it is unknown how old he was at the time of his death, it should be safe to say it was over 100.