Formula for calculating months remaining in the year

Formula for calculating months remaining in the year

I'm having difficulty creating a formula field to achieve the following goal: I want to calculate the total value of a monthly contract for the remaining months in the fiscal year of the start of that contract.  I have a monthly revenue field and a start date field, so what I want to do is 
1) identify the fiscal year end of the year of the start date
2) identify the total number of months, rounded down, between the fiscal year end and the start date of the contract.
3) multiply the monthly revenue by the number of months remaining.  

With a June 30th Fiscal Year end, this means that a 6/15/2016 start date for a 5k/month contract would calculate as 0k total value.  A 7/1/2016 start date for the same contract would calculate as 60k total value.  

As a first step, I can't even figure out how to generate the fiscal year for any particular date.  Any advice on how to proceed?