Bearded Dragons live for an average of 8-12 years depending on their quality of lives. If they were kept with the correct lighting, the temperature were maintained and had a well balanced diet then you can expect your dragon to live longer than a dragon that were kept in less optimum conditions. Life expectancy can go to 10-15 in some cases. However, if you have a female that has been repeatedly bred then her life span can be expected to be quite short.
Bearded Dragons grow on average 16-24 inches from nose to tail. They grow rapidly during the first year from 4 inches hatchling to adult size within a year.
This growth chart is based on average bearded dragons in captivity: