ok, so I know there is no accurate age - weight charts because snakes grow at different rates.

but is there somewhere that has a chart for length to weight ratios?
meaning something like saying a snake that is X" long should weigh somewhere between Y and Z grams?

and how would I go about guesstimating the age of my snake?

my BP is roughly 20" long (can't say exactly because he wasn't interested in being stretched out near the ruler ) and weighs 129g.

thanks in advance for any answers.