Rodi, I am trying to understand this better - "fixed tax percentage".
For FRIP, based on my reading of the methodology, I thought that the tax rate could be 15% one year, 25% another, based on what it thought the income would be.
As an example, if FRIP thought my income for 2015 was less than @94,000 it would use calculations of less than 15%. If FRIP thought my income for 2015 was $100,000 it would use calculations of less than 25%. And all these numbers were best estimates for FRIP of course.
I probably didn't word that correctly... Under the inputs you enter your effective federal and state tax rate. - Since it says "effective" rather than "marginal" - I said "fixed".... Obviously there are some nuances - but I assume it is applying the "effective" tax rate, not looking at your income sources specifically.
I see from other threads there are differences between already retired, and still working - perhaps this is one of those differences. Off to go play with the tool.