How this calculator works
A Roth conversion moves pre-tax traditional IRA dollars into a Roth IRA. You generally owe income tax on the converted amount in the year of the conversion, but qualified Roth withdrawals later can be tax-free. This calculator answers: Should I convert some or all of my traditional IRA this year?
It estimates:
- Additional taxable income from the conversion—the converted amount added to your ordinary income.
- Federal tax on the conversion using 2025 brackets and standard deduction on your current income—or a marginal rate you enter manually for simplified planning.
- Net Roth balance after conversion, depending on whether you pay tax from existing savings or from withholding inside the IRA.
- Projected values at retirement for the Roth path vs. leaving the money in traditional (after tax at your expected retirement bracket).
- Break-even timing—how many years until the Roth path produces more after-tax wealth.
Conversions tend to work best in low-income years—job change, sabbatical, early retirement gap before Social Security and RMDs—or when your current tax rate is lower than the rate you expect on the same dollars in retirement. Paying tax from outside the IRA keeps more money compounding tax-free inside the Roth.
This is not tax advice. State taxes, pro-rata rules for mixed after-tax and pre-tax IRA basis, IRMAA Medicare surcharges, and ACA premium tax credits are not modeled. Consult a professional before large conversions.
See the Roth vs. traditional IRA calculator for ongoing contribution choices and the RMD calculator for required minimum distributions that conversions can reduce later.
What affects the result
Several levers change whether a conversion pays off over your horizon.
- Conversion size — Larger conversions jump into higher brackets and increase tax due this year. Partial conversions are common to fill lower brackets without spanning into the next tier.
- Current income — Higher income raises the marginal rate applied to the conversion when using auto-calculated brackets.
- Filing status — Single vs. married filing jointly changes bracket widths and standard deduction ($15,000 vs. $30,000 in 2025).
- Retirement tax rate — If you expect higher rates later—RMDs, pension, Social Security taxation—paying tax now at a lower rate can help if you can afford the tax bill without depleting emergency savings.
- Investment return — Higher growth magnifies the value of tax-free compounding in the Roth path.
- Tax payment source — Paying from savings leaves the full conversion in the Roth. Paying from the conversion itself shrinks the Roth starting balance and delays break-even.
- Years until retirement — More time for tax-free growth helps the Roth path; break-even may still take many years if today's tax rate is high.
Partial conversions across multiple tax years often beat one large conversion that spikes into the 32% or 35% bracket.
Real-world examples
Example 1: Low-income gap year. You earn $45,000 in a sabbatical year and convert $40,000 while single. Auto-calculated brackets may produce a lower effective conversion rate than the 24% you expect in retirement. Paying tax from savings keeps $40,000 working in the Roth.
Example 2: Pay tax from the conversion. A $100,000 conversion at 22% effective tax paid from the IRA leaves $78,000 in the Roth. Break-even vs. keeping traditional depends on years to retirement and your future bracket—paying externally usually improves outcomes.
Example 3: High current bracket. Converting during peak earning years at 32% when you expect 22% in retirement may reduce lifetime tax—but only if you can pay the tax without sacrificing liquidity or match opportunities elsewhere.
Example 4: Partial conversion ladder. Converting $25,000 per year for four years instead of $100,000 at once may keep more of each conversion in the 12% and 22% bands. Run the calculator at each amount you are considering.
Example 5: Early retirement before RMDs. Converting in the 60–72 window before Social Security and large RMDs begin can fill lower brackets systematically—this calculator helps size each year's conversion, not the full multi-year ladder.
Common mistakes
Converting without cash to pay the tax. Selling investments or withholding from the conversion reduces long-term benefits. Plan the tax payment before converting.
Ignoring pro-rata rules. If you hold other pre-tax IRA balances, a backdoor Roth or partial conversion may be partly taxable in proportion to all IRA assets—not just the amount you intended to convert.
Forgetting the 5-year rule. Each conversion starts its own five-year clock for penalty-free access to conversion principal before age 59½. Qualified earnings follow separate rules.
Skipping state tax and IRMAA. A large conversion can increase Medicare premiums two years later (IRMAA) and state tax bills in high-tax states.
Assuming Roth always wins. If your retirement tax rate is lower than today, staying traditional may leave more after-tax wealth. Run both paths at realistic brackets.
Converting while receiving ACA subsidies. Conversion income can reduce premium tax credits—this calculator does not model health insurance marketplace effects.
When to use this calculator
Use it when weighing a year-end Roth conversion, planning a low-income year, or comparing partial vs. full conversion amounts before executing with your custodian.
Pair with the retirement projection calculator for broader savings growth, the retirement withdrawal calculator for drawdown planning, and the income tax estimator for how conversion income stacks on wages.
Read the Roth vs. traditional IRA guide for account choice fundamentals before converting existing balances.
Skip this estimate for complex situations involving substantial after-tax IRA basis, multi-state residency, estate planning with large IRAs, or trust-owned IRAs—those need personalized advice.
Related calculators
- Roth vs. traditional IRA calculator — compare account types for ongoing contributions, not only conversions.
- Retirement projection calculator — project portfolio growth with contributions and returns across accounts.
- Retirement withdrawal calculator — model inflation-adjusted withdrawals and portfolio longevity.
- RMD calculator — estimate required minimum distributions from tax-deferred accounts conversions may reduce later.
- Income tax estimator — see how conversion income combines with salary for bracket planning.
Related guides
- Roth vs. traditional IRA — how each account type is taxed and who each may suit before you convert.
- Safe retirement withdrawals — withdrawal rates, sequence risk, and tax-aware drawdown strategies after conversion.
FAQ
What is a Roth conversion?
A Roth conversion moves money from a traditional IRA (or similar pre-tax account) into a Roth IRA. You generally owe income tax on the converted amount in the year of the conversion, but qualified Roth withdrawals can be tax-free later.
Do I owe taxes on a Roth conversion?
Yes. The converted amount is usually included in your taxable income for the year. This calculator estimates federal tax using 2025 brackets or a rate you enter manually.
Can I convert only part of my traditional IRA?
Yes. Partial conversions are allowed. Model a partial amount by entering only the portion you plan to convert this year.
What is a "backdoor Roth" and does this calculator cover it?
A backdoor Roth typically involves nondeductible traditional IRA contributions followed by a conversion to Roth. Pro-rata rules may tax part of the conversion if you hold other pre-tax IRA balances. This tool models a taxable conversion amount you enter—it does not perform pro-rata allocation.
Is there an income limit on Roth conversions?
There is no income limit on converting traditional IRA assets to Roth. Income limits may still apply to direct Roth IRA contributions, which is why backdoor strategies exist.
What is the 5-year rule for Roth conversions?
Converted amounts have their own five-year clock for penalty-free access to conversion principal before age 59½. Each conversion year starts a new five-year period. This calculator does not model early withdrawal penalties.
Should I pay the tax from outside the IRA?
Paying from existing savings keeps the full converted amount in the Roth, which usually improves long-term results compared with withholding from the conversion itself.
Does this include state taxes or IRMAA?
No. State taxes, Medicare IRMAA surcharges, and ACA premium credit effects are not modeled. Large conversions can trigger those costs—consult a tax advisor.