@Kipmc7 it is a rather simple exercise.
1) decide what tax bracket you can stomach.
2) decide (if you are on Medicare) what tranche of IRMAA you can stomach.
3) convert enough to get to the top of 1) and 2).
4) what is your objective? There is a growing thought that folks are moving towards larger Roth conversions since their children (who normally inherit) only have 10 years to liqudate the inherited Trad IRAs and many may have to do that during their high earning years. Hence parents can convert at a lower tax rate than their children may be able to.
Good IRMAA explanation:
https://thefinancebuff.com/medicare-irmaa-income-brackets.html
@fanfare <<Generally, these surtaxes will be avoided, as well tax on Social Security, if you are funding your retirment out of Roth IRA money.>>
can you explain please? Maybe I misunderstand what you are meaning?
The Roth money is the most valuable financial asset vehicle as there is no tax on exiting from the Roth (it was already paid!), so best to consume all nonqual investments first (only taxed at capital gains rates), then Trad IRA dollars (which there is really no way out of the tax, short of QCD), and leave the Roth dollars to grow tax free and consumed last.
Better to pay tax I can't get out of than consume assets (roth) where I have already paid the tax but can enjoy tax free returns going forward.
