How can you tell how old a bearded dragon is?

It is really difficult to tell how old a dragon is. They grow at different rates and different breeds are different sizes. An adult dragon is generally more that 16 inches nose to tail. In my experience a 6 month old is anywhere from 10-16 inches. 2 months old around 5-7 inches. Sorry I can't help more.... Feel free to send me a message if you have more specific information that may help to figure it out.