Miles Transfer Calculator

Here is a very useful loyalty program Points/Mileage converter calculator. It shows you how many miles in one program will transfer into in another program
Example: I want to make a ticket from NY JFK to London LHR on American Airlines with my AAdvantage Miles, which usually costs 40,000 miles but i am short 12,000 Miles, How many Starwood points (or almost any other program)would I need to transfer to get those 12,000 AAdvantage Miles.
Calculator Link