How much does a teener of crystal meth weight?

It really depends on who is buying it. A 20 is a 20 it can weigh anywhere from .15g to .25g. It is supposed to weigh .25g but most people just eyeball it so unless you request a 1/4g you will pretty much get what you get. That has always been my experience. So if you are worried about it be specific and ask for a quarter or a half or a G.