The lifespan of a captive parakeet is typically between 5-10 years depending on their care and diet. Some are reported to live for 15 years under optimum conditions.
Not long-lived for parrots, a budgie can still live as long as a dog. Overbreeding, for color and type, has significantly lowered the expected lifespan, however. While it’s possible a budgie can live as long as 12 years, the average is more around 6 or 7.
Keeping parrots of any species on an all-seed diet will possibly cut their lifespan in half, not to mention cause you a lot of behavioral problems. Birds that don’t eat healthily don’t feel healthy – and they will take all that “feeling bad” out on you and your family members.
English budgies tend to have somewhat shorter lifespans, being that much more overbred than Americans.