Roth Conversion Calculator
Estimate the tax cost of converting traditional IRA money to a Roth and compare long-run after-tax outcomes.
Your details
Comparison
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Tax cost of the conversion
$11,518
23.0% effective rate — marginal bracket 24%
Includes your inputs, the full breakdown, and every row of the table.
Federal tax
$11,518
State tax
$0
Roth value in 20 yrs
$193,484
Tax-free at withdrawal
Traditional after-tax value
$188,803
Taxed at 22%
- Converted amount
- $50,000
- Federal tax on conversion
- $11,518
- State tax on conversion
- $0
- Total tax due this year
- $11,518
- Roth advantage at withdrawal
- $4,681
What this means
- Converting looks favorable by roughly $4,681 under these assumptions, mainly because your expected retirement rate (22%) is close to or above today's marginal rate (24%).
- Paying the tax from outside cash is what makes conversions powerful: the full balance keeps compounding while the tax bill comes from elsewhere.
- Conversions are irreversible — recharacterization of conversions was eliminated by the 2017 tax law.
How the roth conversion calculation works
A Roth conversion moves money from a pre-tax IRA or 401(k) into a Roth account. You pay ordinary income tax on the converted amount today in exchange for tax-free growth and tax-free qualified withdrawals later, with no required minimum distributions during your lifetime.
The core question is simple: is your marginal rate today lower than the rate you expect to pay when you eventually withdraw? Low-income years — early retirement before Social Security starts, a sabbatical, a business loss year — are when conversions are most valuable, because you can fill up the lower brackets deliberately.
Frequently asked questions
Does a conversion have a five-year rule?
Yes. Each conversion has its own five-year clock before the converted principal can be withdrawn penalty-free if you are under 59½. Earnings follow the separate five-year rule for the Roth account itself.
Can a conversion raise my Medicare premiums?
Yes. Conversion income counts toward modified AGI for IRMAA, which is assessed on a two-year lookback. If you are 63 or older, a large conversion can raise Part B and Part D premiums later.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.