Formula to Calculate Fiscal Year Contract Amount

Formula to Calculate Fiscal Year Contract Amount

I am having trouble creating a formula to determine the revenue generated for an opportunity within a fiscal year.

For Example:
${Opportunities.Monthly Recurring Fees} will generate $2,500 a month in revenue.  Fiscal Year Ends 3/31. If contract closes on ${Opportunities.Closing Date}, how much revenue will the opportunity generate between ${Opportunities.Closing Date} and 3/31 of next fiscal year end.

The issue I have is determining the number of months between the closing date and the fiscal year end.

How would I make this happen? 

Thanks!