Roth Conversion Room Calculator: the facts

1. A Roth conversion is ordinary income in the year it is done. For 2026 the 22 percent bracket runs from $50,400 to $105,700 of taxable income on a single return and from $100,800 to $211,400 on a joint return; the 24 percent bracket runs to $201,775 and $403,550.
2. Taxable income is adjusted gross income less deductions; the 2026 standard deduction is $16,100 single and $32,200 joint. The room in a bracket is the bracket's top minus taxable income.
3. A single filer with $100,000 of adjusted gross income has $83,900 of taxable income and $21,800 of room at 22 percent; converting $30,000 costs $6,764, because the last $8,200 is taxed at 24 percent.
4. Medicare premiums are set by adjusted gross income from two years earlier, in tiers with hard edges: the first tier begins above $109,000 single and $218,000 joint, and one dollar over moves the whole premium up a step for the year.
5. Because the tiers apply to adjusted gross income and the brackets to taxable income, a conversion that fits neatly in a bracket can still cross a Medicare tier; the two lines sit $16,100 apart on a single return.
6. Conversions cannot be undone: since 2018 there is no recharacterization. The room is measured once, with the year's income known, and the conversion is sized to it.

Educational only, not investment, tax, or legal advice. Results are hypothetical estimates that vary with each use and over time and are not guaranteed accurate or complete. Using this tool creates no client relationship with Considerate Capital, and the site that linked here is not affiliated with it. By using it you agree to the tool terms.