Married husband age 71 will be in 22% tax bracket in 2018 has 3 non-deductible traditional IRA’s cumulative cost (ie amount contributed over the years)
about $ 100,000 market value $300,000 as of Nov 30, 2018. Wants to convert before 12/31/18, from $7,000 to $ 10,000 from a non-deductible traditional IRA with a cumulative cost (basis) of $10,000 and about $30,000 value ( the IRA investment is in a CD).

1. Tax rate this year will be 22%. Therefore what does he pay tax on if he converts $10,000; the $10,000 cost basis of his non-deductible traditional IRA ? So is the tax $10,000 x 22%. It is important to know because if the conversion is taxable at more than $10,000 it will put his taxable income over the 22% tax bracket
2. Or is the computation of the taxable amount on the Roth conversion different than above
3. If the best $ answer to convert is different to keep the taxable amount after conversion no more than $10,000 to
not exceed the conversion tax at the 22% rate, let me know. At this time
based on the projections received he can have additional taxable income of from $7,000 to $ 10,000 and not
go over the 22% tax bracket.
4. Or is the taxable amount computed as ( $7000 to $ 10,000 whichever he decides) divided by $100,000 times whatever amount is converted. Or is there another formula to compute the taxable amount of this traditional IRA to Roth IRA conversion.
5. If the answer requires to take some money ( but not all of it) from one of the 3 available IRA CD’s is that allowed.
That is if the answer is to convert $ 8,500 and one of the 3 IRA’s has $ 25,000 is that acceptable to convert a portion of a traditional IRA to a Roth with no problems