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Roth Conversion Calculator

Find out if Roth conversions could reduce your lifetime taxes — free, no sign-up required.

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Disclaimer: This tool provides educational estimates only. Actual Roth conversion outcomes depend on detailed tax situations. Consult a qualified tax professional.

This is a screening tool. It answers one question — do Roth conversions deserve serious attention in your situation, or not — and it shows you the reasoning behind the answer instead of just a verdict. It is deliberately not a tax calculation, and the section below is precise about where it stops.

What the tool does, and where it stops

You answer five questions: your age, whether you have retired, roughly how large your pretax balances are, your current annual income, and your filing status. It returns a candidacy signal — strong, moderate, or weak — along with the specific reasons behind that signal and a rough estimate of how many years your low-income conversion window may run.

It also shows a bracket-headroom figure: the distance from the income you entered up to a federal bracket ceiling. **Read that number as an order of magnitude, not an answer.** Two simplifications matter. It compares your income to the ceiling without subtracting your standard deduction, which understates your true headroom. And it measures only against the 22% and 24% ceilings, so if you are in a lower bracket, the figure shown is not the ceiling you would actually plan against.

We would rather tell you that than let you act on a number believing it is more precise than it is. What a screen is genuinely good for is deciding whether this is worth your time — and if it says yes, the next step is a real calculation against your actual return.

Why "how much" is the harder half of the question

Whether to convert at all is usually the easier call: if your marginal rate today is lower than your expected rate later, converting is favorable. Sizing is where the real money is, because the cost of a conversion is not smooth. It steps.

Federal brackets step. State income tax may step, or may not apply at all. And for anyone near Medicare age, an income-related premium adjustment is a genuine cliff rather than a slope — one dollar over a tier boundary triggers the entire surcharge for that tier, assessed from the income you reported two years earlier. A conversion sized to the bracket but blind to that boundary can cost more than it saves.

That is why no screening tool can give you the number, and why "convert until just under the next threshold" is a more useful rule than any fixed figure. The right amount changes every year even when your plan does not.

What this tool does and does not model

It estimates

  • Whether your situation structurally favors conversions, with the reasons shown
  • A rough estimate of how many years your low-income window may run
  • An order-of-magnitude bracket-headroom figure, measured against the 22% and 24% ceilings

It does not model

  • Any tax computation — it never asks for a conversion amount and never returns tax owed
  • Your standard deduction, so the headroom figure understates your real headroom
  • Brackets below 22%, so the ceiling shown may not be the one that binds for you
  • State and local income tax — which for some filers is the largest single factor
  • Your existing IRA basis and the pro-rata rule across all pretax IRAs
  • Net Investment Income Tax, and ACA premium tax credits if you are under 65
  • Capital gains stacking, QBI interactions, and the taxable-Social-Security calculation

Frequently Asked Questions

Sizing and estimation questions about Roth conversions. For what a conversion is and how the five-year rule works, see Roth Conversion Basics below.

  • How much should I convert to a Roth in one year?

    The common approach is to convert up to the top of your current tax bracket and stop, so every converted dollar is taxed at a rate you already know. If you are close to Medicare age, the tighter ceiling is usually the next income-tier boundary rather than the bracket. This tool will not give you that figure — it screens whether the question is worth your time. Getting the number itself takes your actual return.

  • What does this calculator actually estimate?

    A candidacy signal — strong, moderate, or weak — plus the reasons behind it, a rough count of the years your low-income window may run, and an order-of-magnitude bracket-headroom figure. It is not a tax computation: it never asks for a conversion amount and never returns tax owed. The headroom figure also skips your standard deduction and measures only against the 22% and 24% ceilings, so treat it as a scale, not an answer.

  • Does the estimate include state income tax?

    No. State treatment varies too much to model generically — several states levy no income tax at all, while others tax conversions as ordinary income at rates that can exceed the federal difference you are trying to capture. If you live in a taxing state, add your state marginal rate to the cost before deciding.

  • Are there income thresholds the bracket math misses?

    Yes, and one of them is a cliff rather than a slope. For anyone at or near Medicare age, an income-related premium adjustment is assessed in tiers based on the income you reported two years earlier, so crossing a tier boundary by a single dollar triggers that entire tier. The calculator does not model it. If you are within a couple of years of 65, check your distance to the next tier boundary before sizing a conversion to the bracket alone.

  • Do I need an account or have to enter identifying information?

    No. There is no account, no email requirement, and nothing that identifies you. Do not enter your Social Security number, Medicare number, or account numbers — no legitimate retirement calculator needs them, here or anywhere else.

  • When is the conversion window usually widest?

    In the years after wage income stops and before RMDs begin — and, if you are delaying Social Security, before those benefits start. Income is temporarily low in that stretch, so the same conversion costs less tax. The RMD age depends on your birth year, so it is worth confirming yours rather than assuming.

  • Can I change my mind after converting?

    No. Recharacterizing a conversion was eliminated for conversions made in 2018 and later, so a conversion is irreversible once done. That is the main argument for converting in measured annual amounts rather than one large transfer.

  • Is this personalized tax advice?

    No. NestPilot Foundation is a 501(c)(3) educational nonprofit. We sell nothing, take no fees, and receive no commissions. This is education and arithmetic you can verify — for a decision this size, confirm the numbers against your actual return with a qualified tax professional.

Primary Sources

Read more about Roth conversions

Last reviewed 2026-08-12. NestPilot Foundation is a 501(c)(3) nonprofit. We sell nothing, take no fees, and receive no commissions.