Roth IRA Conversion Calculator
Fully taxable IRA comparison for Single or Head of Household. Equal-resource projections assume tax-free Roth withdrawals; eligibility is not determined. See assumptions and limitations.
Inputs
Context and limit for the gross IRA amount. The unconverted remainder is excluded from both strategies. Up to $10 million.
Fully taxable amount reaching Roth. Tax is paid from additional outside cash. Cannot exceed the entered IRA balance.
Whole years, 0–119. Used only to set the projection horizon.
Whole years up to 120; later than current age, with a 1–100 year horizon. Does not establish withdrawal qualification.
Enter modeled federal taxable income before this conversion, after your baseline deductions. All entered income is treated as ordinary income. No standard deduction is subtracted again and AGI is not reconstructed. If deductions exceed baseline income, this model does not carry unused deductions forward to offset the conversion. Up to $10 million.
Single and Head of Household only. Active brackets are disclosed in Tax rules & sources.
Constant annual compounding, −50% to 20%. Same return for each modeled asset; no market forecast, fees, inflation or outside-account tax drag.
Outside cash adds the same cash to the no-conversion alternative. IRA assets reduces the amount reaching Roth within the gross removal.
Break-even future tax rate
22.77%
The future effective withdrawal tax rate where the two strategies have equal modeled after-tax wealth.
Above the unrounded modeled break-even rate, the Roth scenario has higher modeled after-tax wealth; below it, the no-conversion scenario has higher modeled wealth. The displayed rate is rounded, not a recommendation.
U.S. federal · Single
- Conversion amount
- $50,000.00
- Amount reaching Roth / taxable conversion portion
- $50,000.00
- Total modeled taxable IRA amount
- $50,000.00
- Modeled incremental federal tax today
- $11,386.00
- Tax funding source
- Outside cash
- Projection years
- 20
- Assumed annual return
- 5%
Return and horizon change projected wealth, but cancel out of this break-even rate because every asset uses the same growth factor.
Fully taxable IRA assumption. IRA basis/pro-rata taxation is not modeled. State and local taxes are excluded.
Future effective withdrawal tax rate
User-entered effective tax on the entire modeled traditional IRA withdrawal, 0–100%. This is not a future marginal bracket or a tax-law prediction.
Selected future effective rate: 25%.
- Projected Roth after-tax wealth
- $132,664.89
- Projected no-conversion after-tax wealth
- $129,709.11
- Modeled difference (Roth minus no conversion)
- $2,955.77
Roth modeled after-tax wealth is higher by $2,955.77 at the selected future effective rate.
No-conversion components: $99,498.66 traditional IRA after tax + $30,210.45 alternative outside cash.
Actual tax results may differ materially. State and local taxes are excluded. Also excluded: credits; deduction changes affected by AGI; itemized deductions; QBI interactions; AMT; NIIT; capital gains and qualified-dividend interactions; Social Security taxation; Medicare IRMAA; ACA subsidy effects; RMD calculations; withholding; estimated-tax requirements and safe harbors; penalties; future tax law; account-specific eligibility; and withdrawal consequences.
Accepted comparison assumptions
USD; Single; IRA balance $250,000.00; gross IRA allocation $50,000.00; baseline taxable income $75,000.00; ages 50 to 70; 20 years; return 5%; funding: Outside cash. Unconverted balance $200,000.00 is excluded from both strategies.
Same constant annual return for Roth, traditional IRA and alternative outside cash; taxable-account tax drag, fees and inflation are ignored. Roth wealth assumes tax-free withdrawal; qualification and penalties are not determined. Ages set the horizon only, not RMDs, withdrawal eligibility or five-year-rule compliance.
Current modeled tax: $22,598.00 after the gross IRA amount − $11,212.00 baseline = $11,386.00. No standard deduction is subtracted again.
Why is my break-even rate 22.77%?
The conversion creates $11,386.00 of modeled federal tax today. Outside cash funds it, so the full $50,000.00 reaches Roth. For equal starting resources, the no-conversion scenario also invests the $11,386.00 of outside cash it did not spend on tax. Equality occurs at 22.77% (rounded): modeled tax divided by gross IRA amount. The common growth factor cancels in both funding modes, so return and horizon change wealth amounts but not this break-even rate.
Future-rate sensitivity
Rates around the unrounded break-even, bounded to 0–100%. Wealth is calculated at each row’s unrounded rate; displayed percentages and money are rounded.
| Future effective rate | Roth wealth | No-conversion wealth | Difference |
|---|---|---|---|
| 16.77% | $132,664.89 | $140,624.78 | -$7,959.89 |
| 20.77% | $132,664.89 | $135,318.18 | -$2,653.30 |
| 22.77% — Break-even | $132,664.89 | $132,664.89 | $0.00 |
| 24.77% | $132,664.89 | $130,011.59 | $2,653.30 |
| 28.77% | $132,664.89 | $124,704.99 | $7,959.89 |
Federal bracket space
Current modeled marginal bracket — rate on the next additional dollar: 22%.
Modeled taxable-income room before the next federal bracket: $30,700.00. Next threshold: $105,700.00. Under the fully taxable assumption, the same gross conversion amount fills that room. This is descriptive arithmetic, not a suggested conversion.
In IRA-funded mode this room applies to the total taxable removal, including the tax-funded distribution.
Federal bracket allocation
The total modeled taxable IRA amount is allocated below. In IRA-funded mode this includes both the converted and tax-funded portions. Each portion uses its applicable federal ordinary-income rate.
| Federal rate | Taxable IRA amount in bracket | Modeled tax on portion |
|---|---|---|
| 22% | $30,700.00 | $6,754.00 |
| 24% | $19,300.00 | $4,632.00 |
| Total | $50,000.00 | $11,386.00 |
Unrounded progressive arithmetic; displayed rows can differ by a cent when summed.
Federal ordinary-income schedule — Single
| Taxable-income band | Rate |
|---|---|
| From $0 through $12,400.00 | 10% |
| Over $12,400.00 through $50,400.00 | 12% |
| Over $50,400.00 through $105,700.00 | 22% |
| Over $105,700.00 through $201,775.00 | 24% |
| Over $201,775.00 through $256,225.00 | 32% |
| Over $256,225.00 through $640,600.00 | 35% |
| Over $640,600.00 — no upper threshold | 37% |
About this calculator
Compare modeled Roth and no-conversion wealth, including U.S. federal tax and equal tax-funding resources. Explore the break-even future effective withdrawal tax rate.
Simplified economic comparison, not a tax return, tax advice, investment advice or a recommendation to convert. Only the entered IRA amount and its tax-funding resources are compared; the unconverted remainder is excluded from both strategies.
IRA basis/pro-rata taxation is not modeled. A conversion involving nondeductible IRA basis may have a different taxable amount. This estimator assumes the entire amount is taxable ordinary income; it does not determine conversion eligibility.
Same constant annual return for Roth, traditional IRA and alternative outside cash; taxable-account tax drag, fees and inflation are ignored. Roth wealth assumes tax-free withdrawal; qualification and penalties are not determined. Ages set the horizon only, not RMDs, withdrawal eligibility or five-year-rule compliance.
What this Roth conversion calculator compares
Simplified economic comparison, not a tax return, tax advice, investment advice or a recommendation to convert. Only the entered IRA amount and its tax-funding resources are compared; the unconverted remainder is excluded from both strategies.
Enter a traditional IRA balance, the gross IRA amount allocated to this comparison, ages, baseline taxable income, filing status, annual return and tax funding. Then explore a future effective withdrawal tax rate. The original IRA balance validates the allocated amount; its unconverted remainder is excluded from both sides.
Enter modeled federal taxable income before this conversion, after your baseline deductions. All entered income is treated as ordinary income. No standard deduction is subtracted again and AGI is not reconstructed. If deductions exceed baseline income, this model does not carry unused deductions forward to offset the conversion.
Only Single and Head of Household are supported. Neither filing-status eligibility nor conversion eligibility is determined. All IRA money in this comparison is assumed to have no nondeductible basis.
Tax and equal-resource comparison methodology
Let C be the gross IRA amount allocated, T the incremental federal tax, n the comparison age minus current age, r the annual return, F = (1 + r)n, and f the selected future effective withdrawal tax rate. Current tax T = federal ordinary-income tax on (baseline taxable income + C) − tax on baseline income. Each bracket applies only to its share. No standard deduction is subtracted again.
Outside cash: Roth wealth = C × F. No-conversion wealth = C × F × (1 − f) + T × F. The additional term retains the outside cash that was not spent on conversion tax. Both strategies start with C in the IRA plus T in cash.
IRA assets: Roth wealth = (C − T) × F. No-conversion wealth = C × F × (1 − f). Both start with C in the IRA. The gross removal C includes the converted portion and the tax-funded distribution; both are assumed taxable, so taxable income increases by C, not C − T. This is not a net-conversion gross-up calculation.
In either mode the difference is F × (C × f − T). For positive C and F, break-even f = T ÷ C. Return and horizon cancel; they change projected wealth but not the break-even percentage under these equal-return assumptions. The calculator verifies equality through the central comparison engine. The displayed percentage is rounded; the sensitivity break-even row uses the unrounded rate.
Same constant annual return for Roth, traditional IRA and alternative outside cash; taxable-account tax drag, fees and inflation are ignored. Roth wealth assumes tax-free withdrawal; qualification and penalties are not determined. Ages set the horizon only, not RMDs, withdrawal eligibility or five-year-rule compliance.
IRA tax funding, basis and distribution boundaries
Simplified economic funding model: gross IRA removal includes both the amount reaching Roth and the amount used for tax. Both are assumed fully taxable; their sum is the tax base. This does not reproduce actual withholding/distribution taxation. Retained or withheld amounts may have separate income-tax and additional-tax consequences. Early-distribution additional tax, withholding requirements, conversion eligibility, five-year consequences and whether a specific structure is permitted or advisable are not determined.
IRA basis/pro-rata taxation is not modeled. A conversion involving nondeductible IRA basis may have a different taxable amount. This estimator assumes the entire amount is taxable ordinary income; it does not determine conversion eligibility.
Amounts actually converted and amounts distributed for tax are distinct for reporting. This calculator combines their fully taxable ordinary-income effect only. It does not complete Form 8606, model nondeductible basis, gross up a desired net deposit, or determine an actual withholding election.
RMD amounts cannot be converted. Traditional IRA owners can have lifetime RMD obligations; original Roth IRA owners do not have lifetime RMDs. This page computes no RMD amount and does not check whether your input includes one. Separate conversion five-year rules and Roth qualified-distribution rules can matter. The projection assumes tax-free Roth withdrawal without establishing that the conditions are met.
Worked example
For a Single filer, $75,000 baseline taxable income plus a $50,000 fully taxable conversion gives $11,212 baseline tax and $22,598 after-conversion tax: T = $11,386. Allocation is $30,700 at 22% and $19,300 at 24%. Break-even is $11,386 ÷ $50,000 = 22.772%, displayed as 22.77%.
At 5% annual return over 20 years, F is approximately 2.653297705. With outside cash and a selected 25% future rate, Roth wealth is $132,664.89. No-conversion wealth is $99,498.66 in the traditional IRA after tax plus $30,210.45 in retained outside cash: $129,709.11. The modeled difference is $2,955.77.
With IRA-funded tax, the same $50,000 gross removal splits into $38,614 reaching Roth and $11,386 for tax. Roth wealth is $102,454.44 versus $99,498.66 without conversion, again a $2,955.77 difference and the same 22.772% break-even. These are arithmetic examples, not recommendations.
Limitations, input bounds and privacy
Actual tax results may differ materially. State and local taxes are excluded. Also excluded: credits; deduction changes affected by AGI; itemized deductions; QBI interactions; AMT; NIIT; capital gains and qualified-dividend interactions; Social Security taxation; Medicare IRMAA; ACA subsidy effects; RMD calculations; withholding; estimated-tax requirements and safe harbors; penalties; future tax law; account-specific eligibility; and withdrawal consequences.
No optimal amount, investment-suitability assessment, total-account forecast, estate outcome, tax-law prediction, RMD amount, Medicare premium/IRMAA effect, withdrawal-penalty or Roth-qualification calculation. The user supplies a future effective withdrawal rate; it is not inferred from current brackets or age.
Money inputs accept up to $10 million with at most two decimal places. Ages are whole years from 0–120, with a positive horizon of at most 100 years. Annual return is bounded to −50% through 20%; future effective tax rate is 0–100%. Projected components and totals must stay within $1 trillion. Invalid inputs pause results and exports. A zero conversion has no unique break-even: both resource sets are zero for all future rates.
Unrounded floating-point calculations use an equality tolerance of the larger of $0.000001 and 16 machine-epsilon units of the compared wealth (less than $0.004 at the supported ceiling). Display rounds money to cents and percentages to two decimal places. A selected rounded break-even can leave a small nonzero difference; no exact equality is implied by a rounded display.
All calculations run locally. No Share, financial URL state, local/session storage, cookies, analytics, accounts or calculation requests. Copy includes accepted fields and provenance only, with a manual fallback. Print uses your browser; Reset restores the example and clears validation, rate changes, disclosures and Copy feedback.
Roth conversion calculator FAQ
What does the break-even rate mean?
It is the future effective tax rate on the modeled traditional IRA withdrawal where both strategies have equal after-tax wealth under the stated assumptions. It is not a forecast or a recommendation.
Why do age and return not change the break-even rate?
Every modeled asset grows at the same rate for the same horizon. The common positive growth factor cancels in the equality equation. Age and return still change projected dollar amounts.
What happens to outside cash without conversion?
The no-conversion scenario invests the cash that would otherwise pay conversion tax. It uses the same assumed return with no taxable-account tax drag. Omitting that cash would compare unequal resources.
What does the IRA-funded amount mean?
It is the total gross amount removed, including the amount reaching Roth and the amount allocated to tax. It is not a requested net Roth deposit. Additional tax, withholding requirements and eligibility are not modeled.
Is the entire IRA balance compared?
No. The balance limits the allocated amount. Only that amount and its corresponding tax-funding resources enter the comparison; the unconverted remainder is excluded on both sides.
Is my conversion fully taxable?
The calculator assumes it is. It cannot establish your taxable amount when nondeductible basis or other special rules apply. Consult the official Form 8606 instructions for that boundary.
Does comparison age establish a tax-free Roth withdrawal?
No. Age only sets the horizon. Tax-free Roth withdrawal is an explicit projection assumption, not a qualification finding. Five-year rules, penalties and other conditions are outside the model.
Which filing statuses and taxes are supported?
Single and Head of Household, using the federal ordinary-income schedules disclosed below. State/local taxes, credits, AMT, NIIT and other return interactions are excluded.
What if I enter zero conversion or a negative return?
Zero conversion makes both modeled resource sets zero, so there is no unique break-even. Supported negative returns reduce future amounts but leave the analytical break-even unchanged. Returns at or below −100% are not accepted.
Will the tax rules update automatically?
No. Tax rules are explicitly versioned. A later year requires deliberate source, rule, fixture and content review. Saved comparisons identify the rules used.
Tax rules & sources
Tax rules: 2026 U.S. federal. Tax model: 2026-fully-taxable-v1. Comparison model: 2026-equal-resources-v1. Rules reviewed: 2026-09-27 (September 27, 2026).
These rules are explicitly versioned and are not automatically current. A future release requires deliberate review of federal brackets, relevant IRS forms/instructions, Form 8606 and IRA guidance, funding assumptions, fixtures, sources, methodology and displayed tax year.
- Revenue Procedure 2025-32, section 4.01, Tables 2–3 (opens in a new tab): 2026 Single and Head of Household brackets.
- Publication 590-A (2025), Contributions to Individual Retirement Arrangements (opens in a new tab): conversion taxation and the RMD/conversion boundary.
- Publication 590-B (2025), Distributions from Individual Retirement Arrangements (opens in a new tab): taxable distributions, basis, qualification and five-year-rule boundaries.
- Instructions for Form 8606 (2025) (opens in a new tab): basis and conversion reporting. No basis-aware computation is implemented.
- Rollovers of retirement plan and IRA distributions (opens in a new tab): withholding and amounts not rolled over; the funding model is not withholding advice.
- Retirement plan and IRA required minimum distributions FAQs (opens in a new tab): lifetime RMD treatment for original traditional and Roth IRA owners.
No IRS endorsement or professional tax review is claimed. The equal-resource growth comparison is a disclosed mathematical model, not an IRS-prescribed investment strategy.