How much can I convert to Roth without a higher tax rate?
A Roth conversion means paying tax now on pre-tax savings so later withdrawals are tax-free. Tax brackets work like steps: only the income above a step's line is taxed at the higher rate.
Your result
Medicare check
Open the Medicare IRMAA calculatorHow we calculated it
- Room equals the top of your current bracket minus your taxable income.
- Tax on a conversion is figured slice by slice, each slice at the rate of the bracket it falls into.
Simplified. Conversions can also raise Medicare IRMAA, the taxable part of Social Security and state taxes. This tool covers federal ordinary brackets only.
Common questions
If I cross a bracket, do I pay the higher rate on everything?
No. Only the dollars above the bracket line are taxed at the higher rate.
What is taxable income?
Your income after deductions, shown on Form 1040, line 15. The standard deduction for 2026 is $16,100 single and $32,200 married filing jointly.
Does a Roth conversion affect Medicare premiums?
It can. The converted amount counts as income and may push you over an IRMAA line two years later.
Can I undo a Roth conversion?
No. Recharacterization is no longer allowed, so plan the amount before you convert.