I'm trying to create a formula, where

If a cell = a month, then depending on which month there will be a
calculation.
This is as far as I got and it's wrong
eg.
=if(B2="January",1*2.083)*OR(b2="February",2*2.083 )*OR(b2="March",3*2.083)*OR(b2="April",4*2.083)... ........I need this for 12 months
I can only get a formula that does the first part, and nothing else.
HELP ME PLEASE!!!!