Anavar Dosage?

What is the recommended dosage for Anavar, and is there an equation to figure it out?

I remember hearing a friend of mine saying that there was an equation that was something like Bodyweight X .25 or something to figure out how many mg's per day you should take.

I am aware that Anavar is safe even in very high doses, but I do not want to waste it if there is a specified amount that I should take (not to mention that it is expensive).

Let me know if you are aware of any guidelines. Thank you in advance.