Calculator Plugin

I am looking for a Wordpress plugin calculator that would let me do the following:

A) Number of People In Club (paying membership)
B) Number of People in Club (not paying membership)
C) Price of annual membership
D) Percentage of People that should start paying immediately

I need the calculator to do the following - B x C x D = giving the percentage of increase in yearly fee profits.

Hey, andantesash!

Can you write more detailed specification.