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Roth Conversion Tax Ballpark Calculator

Enter conversion amount, federal rate, state rate, optional NIIT toggle, years and return. See estimated tax and a simplified Roth-versus-leave-traditional growth sketch.

Ballpark only. Ignores brackets stacking, credits, IRMAA, pro-rata rule details and basis. Not tax advice — confirm with a CPA/EA and IRS Pub 590.

What a conversion taxes

Moving pretax retirement dollars to a Roth generally includes the converted amount in taxable income in the conversion year. Paying the tax from non-IRA funds usually preserves more Roth principal than withholding from the converted amount.

What this tool ignores on purpose

Bracket cliffs, deductions, credits, Medicare IRMAA lookbacks, charitable strategies, and the pro-rata rule that affects many backdoor Roth fact patterns. See conversion tax basics and backdoor Roth overview.

Enter rates you actually expect for the slice of income the conversion fills — not a random blog average.

Privacy and honesty

Calculations run locally in your browser on NestEgg. We do not need an account and we do not receive the numbers you type. Advertisers help keep the tools free; ads are labelled. Affiliate links, when present, use rel="sponsored" and are described in the affiliate disclosure.

NestEgg provides educational arithmetic only. Results are estimates. Confirm figures with primary sources and licensed professionals.

Using this tool responsibly

Enter figures from your own documents when you need a serious plan. Change one input at a time when comparing scenarios so cause and effect stay obvious. Revisit after life events or new plan documents.

Write down the scenario you chose and the assumption that mattered most. Bring that short note to a conversation with the right licensed professional for your topic.

Privacy and honesty

Calculations run locally in your browser on NestEgg. We do not need an account and we do not receive the numbers you type. Advertisers help keep the tools free; ads are labelled. Affiliate links, when present, use rel="sponsored" and are described in the affiliate disclosure.

NestEgg provides educational arithmetic only. Results are estimates. Confirm figures with primary sources and licensed professionals.

Using this tool responsibly

Enter figures from your own documents when you need a serious plan. Change one input at a time when comparing scenarios so cause and effect stay obvious. Revisit after life events or new plan documents.

Write down the scenario you chose and the assumption that mattered most. Bring that short note to a conversation with the right licensed professional for your topic.

Privacy and honesty

Calculations run locally in your browser on NestEgg. We do not need an account and we do not receive the numbers you type. Advertisers help keep the tools free; ads are labelled. Affiliate links, when present, use rel="sponsored" and are described in the affiliate disclosure.

NestEgg provides educational arithmetic only. Results are estimates. Confirm figures with primary sources and licensed professionals.

Using this tool responsibly

Enter figures from your own documents when you need a serious plan. Change one input at a time when comparing scenarios so cause and effect stay obvious. Revisit after life events or new plan documents.

Write down the scenario you chose and the assumption that mattered most. Bring that short note to a conversation with the right licensed professional for your topic.

Frequently asked questions

Is NIIT always applicable?

No. It depends on income and investment income rules. The checkbox is optional for stress testing.

Can I undo a conversion?

Recharacterization of conversions was generally eliminated; confirm current IRS rules with a professional.

Sources and further reading