I don’t know of a specific tool for that. There is a What-if worksheet you can use in the Desktop program. If you paid for the Online version you can ask support for the Desktop program. After you take out the RMD each year can’t you just divide the remaining balance by the number of years left? Why 10 years? There is no set time to convert to a ROTH. Or did you inherit this IRA? Then you might have to take it out within 10 years.
