How can you see how old your snake is?

By the number of rattles on his tail and the size of the snake.

You can not tell how old a rattlesnake is by the number or size of the rattle, you actually need tissue and blood samples to tell how old they are. I have done a lot of research on this and have found a bunch of different ideas but the only real way to tell how old one is is to get tissue and blood samples, you can get pretty close by estimating most of the time.