Automatically calculating a rate from a pivot table?

I'm using a pivot table to make numerators and denominators for a public health project. Is there anyway on the pivot table that I can do to take the numerator and denominator and divide them automatically into a rate? I've been just using the tables I created from the pivots and putting it in to a different sheet and adding an additional column to calculate rates. Thanks for your help!

Anyone have any ideas? Thanks for your help!