This should be straightforward, but we need more information to get you a valid
formula.

What do you mean by pro rate?
Is the contract change month a date in mmm format, or 3 alpha characters?
Is an increasing percent a positive number, and a decreasing percent a negative
number?
What months are used to determine the "average of the past revenue amounts"?

What output do you want for each customer -- a single amount? or projected 12
months?
--
Regards,
Fred


"dj479794" wrote in message
...
{Excel 2003}

Each Row is revenue by customer
Each column is a month {jan-07, feb-07, mar-07}
We have historical revenue for each month.
In a seperate column we have an identifier when the contract changes {JUL}.
(Different for each customer)
In another column we have a percent inc/dec/ expected over existing {10%}

How do I set it up so in the cell where I want an ouput. I have a formula
that says if this month or greater fill in a value that is x% more/less than
the average of the past revenue amounts?