Free tool · 2026 brackets
Roth Conversion Tax Calculator
Compare four paths for your retirement dollars — leave it in your IRA/401(k), convert and pay the tax, spread the conversion over several years, or convert with a deduction offset — across your whole retirement.
Starting balance$500,000
Roth Conv. + Offset
Roth Conv. — spread over time
Roth Conv. (pay the tax)
IRA / 401(k) — taxed on withdrawal
Converting and offsetting the tax leaves you with$1.46Mmore in total value by your plan-end age than leaving it in a traditional IRA / 401(k).
Total value = balance left + after-tax income already drawn. The IRA balance is shown pre-tax. The offset path isolates the tax effect — the capital, fees, returns, and risk of the deduction-generating investment are outside this model.
Your results
Four paths, side by side
The same converted dollars by age 90 — after the IRS takes its cut on every path.
1 · Income analysis
How much you could live on each month
Level after-tax income from age 65 to 90, spending the account down to zero.
IRA / 401(k)$5,400/mo
Roth — lump$4,934/mo
Roth — laddered$5,471/mo
Roth + Offset$6,923/mo
2 · Total value
What's left at plan-end
The same $500,000 by your plan-end age, plus the total tax paid getting there.
Do nothing
IRA / 401(k)
Leave it traditional
$1,622,403
total value at plan-end
Started with$500,000
Total tax paid$692,459
After-tax income drawn$1,622,403
Nothing is taxed up front, but every withdrawal is — it stacks on your other retirement income at ~30% plus IRMAA, so you draw more to net the same. The balance left is still pre-tax.
Convert + pay tax
Roth Conv.
Pay the conversion tax up front
$1,282,706
total value at plan-end
Started with$500,000
Total tax paid$179,843
After-tax income drawn$1,282,706
You start with the full $500,000, pay $179,843 of conversion tax from it, and the rest compounds tax-free — every withdrawal afterward is tax-free with no IRMAA.
Convert over time
Roth Conv. — laddered
Spread the conversion across years
$1,687,806
total value at plan-end
Started with$500,000
Total tax paid$170,131
After-tax income drawn$1,687,806
Converting in 5 slices keeps each year in lower brackets — total conversion tax $170,131 vs $179,843 as a lump. Withdrawals are tax-free.
Convert + offset
Roth Conv. + Offset
Deductions absorb most of the conversion tax
$3,081,325
total value at plan-end
Started with$500,000
Total tax paid$59,546
After-tax income drawn$1,716,000
Deductions offset 65% of the conversion tax on each laddered slice — $59,546 is still paid from the account. The rest compounds tax-free, with tax-free withdrawals and no IRMAA.
Under the hood
See the math, year by year
Every figure above traces back to these tables. Pick a path to see its annual calculation — all amounts are per year, with withdrawals starting at the age you set.
Select a path above to see its year-by-year calculation.
Total value = end-of-year balance + cumulative after-tax income withdrawn. Growth is applied to the balance remaining after each year's withdrawal.
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Calculator FAQ
"Account balance" shows what's left invested in each account (the traditional balance is pre-tax). The offset and IRA overlap until withdrawals start, then the IRA falls behind because it must withdraw more to net the same after-tax income. "Total value" adds the after-tax income you've already drawn to that balance, so the IRA tracks the offset during your working years and only diverges once withdrawals begin and each one is taxed. The traditional balance is shown before the income tax still owed on it, so the IRA's true after-tax worth is a bit lower than the line — which is exactly why converting has value.
A conversion adds the converted amount to your ordinary income for the year. This tool stacks the conversion on top of your current taxable income and applies the 2026 federal brackets for your filing status, then adds state tax.
Yes. Traditional withdrawals raise your Modified Adjusted Gross Income, which can push you into higher Medicare IRMAA tiers (2026 starts at $109K single / $218K joint) and raise your Part B and Part D premiums. Qualified Roth withdrawals aren't counted in MAGI, so they don't trigger IRMAA — one of the quieter advantages of converting.
The 2017 rates were made permanent by the 2025 OBBBA, so there's no scheduled increase. But future Congresses could still raise rates given federal deficits, and Roth withdrawals stay tax-free regardless — so a conversion is partly insurance against higher future rates. The Taxes tab lets you assume a rate increase (default +3 points) applied only to the IRA/401(k) path.
No — and this matters. The calculator isolates how conversion taxation affects the retirement account. Generating the offsetting deductions requires committing outside capital to a real, at-risk investment (for example, an oil & gas working interest) with its own fees, returns, liquidity constraints, and possible loss of principal — all of which sit outside this model. The offset path's advantage is a tax-mechanics illustration, not a complete investment-performance comparison. See the strategy guide for what the investment actually involves.
No. This is an educational estimate using 2026 federal brackets, a flat state rate, and simplifying assumptions. It doesn't model the pro-rata rule on after-tax basis, RMDs, Social Security taxation, AMT, inflation-adjusted withdrawals, or the two-year IRMAA lookback. Confirm with a qualified CPA or tax advisor before converting.