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Roth Conversion Simulator

Convert now and pay the tax, or leave it deferred? Side-by-side lifetime after-tax outcomes.

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A Roth conversion means paying tax on a traditional IRA/401(k) balance today so it can grow completely tax-free forever after. It's usually worth it if you expect to be in a higher tax bracket later than you are right now. This shows the exact break-even point.
Shares this exact simulation, sliders and all.
Conversion tax bill today
$24,149
After-tax difference at horizon
$2,079
convert now wins
Breakeven retirement tax rate
21.5%
above this, converting now wins

Converting now breaks even if your tax rate in retirement is above 21.5%. At your assumed 22%, converting now wins by $2,079 after 20 years.

Convert nowStay traditional
$100k$200k$300k$400kyr 0yr 4yr 8yr 12yr 16yr 20
View as table
YearConvert nowStay traditional
0$100,000$102,149
2$114,490$116,426
4$131,080$132,771
6$150,073$151,484
8$171,819$172,909
10$196,715$197,439
12$225,219$225,523
14$257,853$257,677
16$295,216$294,489
18$337,993$336,636
20$386,968$384,889

Methodology & assumptions

  • Uses 2025 federal ordinary-income brackets to compute today's conversion tax bill.
  • The conversion tax is assumed to be paid from outside (already-taxed) cash — paying it from the IRA itself would shrink the converted balance and change the math.
  • The converted Roth balance grows tax-free with no further withdrawal tax, per current qualified-distribution rules.
  • In the 'stay traditional' scenario, the cash that would have paid the conversion tax instead grows in a taxable account, taxed once at the end at a flat 15% long-term capital gains rate — real accounts would owe tax on dividends and turnover along the way.
  • The retirement withdrawal tax rate is a flat assumption you set — it does not model future bracket changes, RMDs, Social Security taxation, or state tax.
  • A constant annual return is applied every year; it does not model sequence-of-returns risk or market volatility.
  • This does not account for Roth income eligibility limits, conversion pro-rata rules for mixed pre/post-tax IRAs, or the 5-year Roth conversion rule.

Educational only

This simulator is for education. It uses simplified assumptions, is not financial, tax, or investment advice, and no result here is a prediction or a recommendation. Talk to a licensed professional before acting.

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