Roth Conversion Calculator

Analyze whether converting a Traditional IRA to a Roth IRA makes financial sense based on your current tax rate, expected retirement rate, and time horizon.

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Advanced Roth Conversion Analysis 2026 IRMAA

2026 IRMAA Tier 1 (single): $109K Tier 1 (MFJ): $218K Tier 1 surcharge cost: ~$1,148/person/yr RMD age: 73 (75 in 2033) CMS · IRS Notice 2025-67
PERSONALIZED FOR YOU

Personalized conversion analysis appears after you Calculate

The Golden Window — Why Ages 60-72 Are Conversion Prime Time

Most retirees experience an unusually low-income period after retiring (60-65) but before Social Security and RMDs begin. This "gap years" window is the highest-leverage conversion opportunity of your life: your bracket may be 12-22% during gap years vs 24-32% before retirement and after RMDs begin. Converting at 12-22% saves 10+ percentage points per dollar converted.

Life StageTypical BracketConversion VerdictWhy
Pre-retirement (50-60)22-32%Probably Don'tPeak earnings — wait for the gap years
Early retirement (60-65)10-22% (low)CONVERT AGGRESSIVELYLowest bracket window. Pre-Medicare = no IRMAA risk.
Medicare years (65-72)12-22%Convert with IRMAA awarenessWatch the $109K/$218K cliffs — but conversions still valuable
Post-RMDs (73+)22-32%Limited windowRMDs raise base income; less bracket space
The conversion math in the gap years: Convert $50,000 at age 62 in the 12% bracket = $6,000 federal tax. That same $50,000, if left as Traditional IRA and withdrawn at age 75 in the 24% bracket, costs $12,000 in tax — $6,000 saved per $50K converted. Multiply by 5-10 conversion years for transformative tax savings.

Why this window is closing

  • Every year delayed shrinks the window. Your IRA balance grows 7%/yr, RMDs grow proportionally, and the bracket space available for conversion shrinks.
  • OBBBA made TCJA rates permanent for 2026+. No more "tax rate scheduled to rise" urgency, but the window mechanics still favor early action.
  • RMD age rises to 75 in 2033 (SECURE 2.0). This actually extends the gap-year window by 2 years for those reaching 73 after 2033 — but most current retirees still face age 73.
  • Surviving spouse implication: If one spouse dies, the survivor files single — much narrower brackets. Aggressive conversion while both spouses are alive can save the survivor from much higher rates.

Sources: IRS Notice 2025-67 for 2026 brackets; SECURE 2.0 §107 for RMD age 73→75 phase-in. The "gap years" framing is canonical in Kitces, Pfau, and Bogleheads literature on tax-efficient withdrawal sequencing.

Multi-Year Conversion Ladder — Spread the Tax Bite

Converting a large pre-tax balance in one year almost always pushes you into higher brackets. The optimal play is a multi-year ladder: convert smaller amounts each year for 5-13 years, filling lower brackets, never crossing into a higher one. This compounds to enormous savings vs a single large conversion.

Single conversion vs 10-year ladder ($1M Trad IRA, MFJ)

StrategyYear 1Average Bracket HitTotal Tax Costvs Optimal
Single $1M conversion at age 62$1,000,000 → bracket 35%~28% blended~$280,000+$130,000 worse
10-year ladder $100K/yr$100K/yr in 22% bracket~22% hold~$220,000+$70,000 worse
13-year ladder $77K/yr$77K/yr in 12% bracket~15% blended~$150,000Optimal

Assumes MFJ filing, 2026 brackets, no other ordinary income (early-retired with portfolio income only). Actual results vary based on Social Security timing, pension, and capital gains.

The "fill the bracket" technique: The 12% bracket for MFJ in 2026 ends at $96,950. If your other income is $30K (interest + LTCG), you have $66,950 of "bracket space" available for a 12% conversion. Convert exactly that much — not more — for 5+ years. By the time you exhaust pre-tax balances, you've paid an effective 11-13% blended rate on what would otherwise have been 22-24% RMDs.

Five-year rule on conversions (penalty-free withdrawal)

Each conversion has its OWN 5-year clock for penalty-free withdrawal of the converted amount (separate from the contribution 5-year rule). Converting at 50? You can withdraw the conversion (penalty-free, since tax already paid) at 55. This is the foundation of FIRE retirement plans — convert pre-tax balances each year, then withdraw the converted amounts 5 years later, all penalty-free even before 59½.

Conversion YearEarliest Penalty-Free WithdrawalFIRE Use Case
2026 conversion at age 50Jan 1, 2031 (age 55)Funds living expense at 55
2027 conversion at age 51Jan 1, 2032 (age 56)Funds living expense at 56
2028 conversion at age 52Jan 1, 2033 (age 57)Funds living expense at 57

Conversion 5-year rule per IRC §408A(d)(3)(F). Each conversion has a separate clock — careful tracking is essential. Converted earnings are subject to BOTH the 5-year rule AND age 59½. Source: IRS Publication 590-B (Distributions from IRAs).

IRMAA Cliff Risk — The Hidden 2-Year Lookback

A Roth conversion increases your MAGI in the conversion year — and that MAGI determines your Medicare premium two years later. Convert in 2026? Your 2028 Medicare premiums are affected. IRMAA brackets are cliffs, not graduated: $1 over a threshold triggers the FULL surcharge for that tier. This is the #1 conversion-planning mistake.

2026 IRMAA Tier (per CMS)Single MAGIMFJ MAGIPart B Surcharge/moPart D Surcharge/moAnnual Cost (couple)
Tier 0 (no surcharge)≤ $109K≤ $218K$0$0$0
Tier 1$109K-$137K$218K-$274K+$81.20+$14.50~$2,297
Tier 2$137K-$170K$274K-$340K+$203.00+$36.30~$5,752
Tier 3$170K-$205K$340K-$410K+$324.80+$58.10~$9,189
Tier 4$205K-$500K$410K-$750K+$446.60+$80.00~$12,638
Tier 5 (top)≥ $500K≥ $750K+$487.00+$91.00~$13,872
The cliff effect — a real example: A couple at $217,000 MAGI pays no IRMAA. Convert $1,001 to Roth, MAGI hits $218,001, and they trigger the full Tier 1 surcharge — $2,297/yr extra for one $1,001 conversion. Effective marginal rate on that last $1,001: 229%. Always leave a $2,000-$5,000 buffer below thresholds to absorb capital gains distributions or unexpected income.

The 2-year lookback timing

  • 2026 MAGI2028 IRMAA (and 2027 MAGI → 2029 IRMAA, etc.)
  • This means conversions done in your 60s (pre-Medicare) have NO IRMAA impact at all — the lookback predates Medicare enrollment.
  • Conversions done at 63 or 64 are particularly powerful — they don't trigger any IRMAA because Medicare hasn't started yet, and the 2-year lookback means even age 63's MAGI is "free" from the IRMAA system.
  • Form SSA-44 ("Life-Changing Event") allows appealing IRMAA based on more recent income if you've retired, divorced, or lost a spouse. Roth conversions do NOT qualify as a life-changing event.

QCD as IRMAA management tool

Qualified Charitable Distributions from IRAs (up to $108,000 in 2026, age 70½+) reduce MAGI dollar-for-dollar — they count toward RMDs but don't show up in MAGI. If you're charitably inclined and near an IRMAA cliff, QCDs are the most efficient tool to stay below the threshold. A $20,000 QCD instead of a $20,000 RMD-then-donation pulls your MAGI down by $20,000 with the same charitable outcome.

Sources: CMS 2026 Medicare Parts A & B Premiums and Deductibles; Kiplinger 2026 IRMAA brackets. QCD limit per IRC §408(d)(8) as adjusted by SECURE 2.0 §307. Annual couple cost figures assume both spouses on Medicare (each pays the surcharge individually).

Breakeven Math — When Does the Conversion Pay Off?

A conversion's value depends on (now-rate vs future-rate), time horizon, and where you pay the conversion tax from. Paying the tax from the converted amount itself is much weaker than paying from outside funds. Below: live calculator + breakeven scenarios.

Trad balance to convert
Marginal rate applied to conversion
Expected retirement bracket
Conversion benefits compound
Investment growth rate
Source of conversion tax payment
At your inputs ($100K convert / 22% now / 24% retire / 20yr / 7%), the comparison:
Convert now (pay $22K tax outside, $100K compounds tax-free)$386,968 tax-free
Don't convert (Trad grows + outside funds compound separately)~$386,140 net + outside growth
Conversion advantage (after-tax)+$92,872

When breakeven flips

ScenarioRecommendationWhy
Now-rate > future-rate by 6+ ptsDon't convertWait — you'll pay less in retirement
Now-rate ≈ future-rateMarginal valueConvert IF other benefits matter (no RMDs, heir tax-free)
Now-rate < future-rate by 5+ ptsConvert aggressivelyEach $ converted saves the bracket-difference forever
Pay tax from conversion itselfReduces value 30-40%Smaller compounding base; only convert if surplus cash to pay tax

Conversion math assumes constant rates and returns over the period. In practice, year-by-year planning with shifting income makes the analysis more complex. The "pay from outside" requirement is critical: paying conversion tax from the conversion itself reduces the converted base by the tax rate, often eliminating the advantage entirely.

Partial vs Full Conversion — How Much Should You Convert?

Almost no one should convert their entire pre-tax balance in one year — that's a recipe for jumping multiple tax brackets and triggering IRMAA. The optimal answer is almost always a partial conversion sized to fit the available bracket space + IRMAA tier ceiling, repeated annually.

Bracket-fill conversion 22%

Convert exactly enough to fill the 22% bracket. 2026 MFJ: 22% bracket ends at $206,700. If other income is $80K, convert ~$126K. Anything more crosses into 24%.

IRMAA-aware conversion $218K

For Medicare-aged: stay below the IRMAA cliff. MFJ Tier 0 ends at $218K. Even if 22% bracket has more room, exceeding $218K costs $2,297/yr in IRMAA — which usually wipes out the conversion's tax savings.

NIIT-aware conversion 3.8%

Conversion itself is NOT subject to the 3.8% Net Investment Income Tax — it's ordinary income. But it DOES raise MAGI, which can push other investment income into NIIT territory. Watch the $250K (MFJ) / $200K (single) NIIT threshold.

Social Security taxability 85%

If you're already receiving SS, conversion income raises provisional income — potentially making more of your SS taxable (up to 85%). For MFJ, the 85% threshold hits at $44K provisional income. SS Tax Calculator →

State residency timing CA→FL

If you plan to move from a high-tax state (CA 13.3%) to a no-tax state (FL/TX/NV/WA), defer conversions until AFTER establishing residency. Save the state tax on every dollar converted.

Annual ladder approach 10yr

Most retirees convert over 5-13 years. Annual amount = (target final-Roth balance) / (years available). Year-by-year monitoring and adjustment based on actual brackets and IRMAA proximity.

2026 Federal Brackets (MFJ)Income RangeRateConversion Strategy
10%$0-$23,85010%Convert aggressively if you can stay here
12%$23,850-$96,95012%Optimal conversion bracket — fill it every year
22%$96,950-$206,70022%Solid conversion bracket; watch IRMAA at $218K MFJ
24%$206,700-$394,60024%Marginal — usually only when comparing to 32% RMDs
32-37%$394,600+32-37%Generally don't convert at these rates

2026 brackets per IRS Notice 2025-67. The "fill the bracket" framework is the consensus approach across financial-planning firms (Vanguard, Fidelity, Schwab) and academic literature on tax-efficient withdrawal sequencing. Year-by-year adjustment is crucial — set-and-forget conversion plans rarely optimize.

Things to Know

Essential concepts for understanding your results

Strategy
When does a Roth conversion make sense?

Convert traditional IRA/401(k) to Roth when your current tax rate is lower than expected future rate. Prime opportunities: early retirement years before Social Security (ages 60-67), years with unusually low income (job transition, sabbatical), years before RMDs begin (age 73), or if you expect tax rates to increase. Convert enough to fill your current bracket but not push into the next — this is the bracket-filling strategy.

Tax Calculation
How much tax do you pay on a Roth conversion?

The converted amount is added to your ordinary income for the year. Converting $50,000 in the 22% bracket costs $11,000 in federal tax plus state tax. Critical: pay the tax from non-IRA funds. Using IRA money to pay tax reduces the amount converted and may trigger a 10% penalty if under 59½. A $50,000 conversion paid with $11,000 from checking is superior to a $39,000 conversion where $11,000 stays taxed in the traditional account.

Five-Year Rule
What is the Roth conversion five-year rule?

Each conversion has its own 5-year clock before converted funds can be withdrawn tax and penalty-free (if under 59½). The clock starts January 1 of the conversion year. A 2026 conversion is accessible penalty-free January 1, 2031. After age 59½, the 5-year rule no longer applies to conversions — only to earnings on contributions. This rule is why early retirees should start conversions early to create accessible Roth funds.

RMD Reduction
How do Roth conversions reduce future RMDs?

Every dollar converted from traditional to Roth permanently exits the RMD calculation. A $500,000 traditional IRA at 73 requires ~$18,900 annual RMD (taxed as income). Converting $200,000 to Roth before 73 reduces the traditional balance to $300,000, cutting RMDs to ~$11,300. Over a 20-year retirement, this saves $150,000+ in RMD-driven taxes. The conversion window between retirement and 73 is the most valuable tax planning period.

What Is a Roth Conversion?

A Roth conversion moves money from a Traditional IRA or 401(k) to a Roth IRA, paying income tax on the converted amount now in exchange for tax-free growth and withdrawals forever. Unlike direct Roth IRA contributions, there are no income limits on conversions — anyone can convert any amount at any time.

Why would you voluntarily pay taxes? Because you are paying at today's known rate to avoid paying at tomorrow's unknown (and potentially higher) rate. If you convert $50,000 in the 22% bracket today, you pay $11,000 in tax. That $50,000 then grows tax-free — at 7% for 20 years, it becomes $193,000 of completely tax-free money. Without conversion, the same $193,000 would be taxed at withdrawal, costing $42,000-$67,000 in taxes at 22-35%.

The math is clear: the longer the money has to grow tax-free, and the higher your future tax rate, the more valuable the conversion. This makes Roth conversions one of the most powerful tax planning strategies available — especially during low-income years.

The Golden Window: When to Convert

Roth conversions are most valuable during years when your taxable income is temporarily low, creating a window to convert at a reduced tax rate:

Early retirement before Social Security (ages 60-67): If you retire at 60 and delay Social Security to 70, you may have 7-10 years with dramatically lower taxable income. This is the classic "Roth conversion window." Convert enough each year to fill up the 12% or 22% bracket — income that would otherwise be taxed at 24%+ when RMDs begin at 73.

Between jobs: A gap year, sabbatical, or career transition drops your income. Convert during this low-bracket year before higher income returns.

Market crashes: After a 30% market drop, your $500,000 Traditional IRA is worth $350,000. Converting now means paying tax on $350,000 instead of $500,000 — saving $33,000 in taxes at the 22% bracket. When the market recovers, the growth is tax-free in your Roth.

Before RMDs begin (age 73): Required Minimum Distributions force taxable withdrawals from Traditional accounts starting at 73. Large RMDs can push you into higher brackets, trigger Medicare IRMAA surcharges, and increase Social Security taxation. Strategic conversions before 73 reduce the Traditional balance, reducing future RMDs.

Before expected tax rate increases: Tax rates are historically low through 2025 (potentially extended). If you believe rates will rise in the future — whether from legislation, higher personal income, or RMDs — converting now locks in the lower rate.

How Much to Convert: The Bracket-Filling Strategy

The optimal conversion amount fills your current tax bracket without pushing you into the next one. This maximizes the tax efficiency of each dollar converted.

Example: A married couple with $60,000 in income (after standard deduction of $32,200 = $27,800 taxable). The 12% bracket extends to $96,950. They can convert $96,950 - $27,800 = $69,150 and pay only 12% on the entire conversion ($8,298 in tax). Going above $96,950 would trigger the 22% rate on excess dollars.

For many retirees in the conversion window, this means converting $50,000-$100,000 per year over 5-10 years — systematically moving their Traditional IRA balance to Roth before RMDs begin. The total tax bill is significant ($25,000-$50,000+) but saves far more in future taxes on decades of growth.

Watch for cascading effects: Conversion income can trigger Medicare IRMAA surcharges (higher premiums for 2 years), increase Social Security taxation, reduce ACA premium subsidies, and affect financial aid calculations. Model the full impact, not just the federal bracket.

Roth Conversion Ladder: Early Retirement Access

The Roth conversion ladder is the primary strategy FIRE practitioners use to access retirement funds before age 59½ without penalties:

Step 1: Convert a year's worth of living expenses from Traditional IRA to Roth IRA (paying taxes from a separate taxable account — never from the conversion itself).

Step 2: Wait 5 years. After 5 years, the converted amount (not earnings) becomes accessible penalty-free and tax-free.

Step 3: Repeat each year. After the initial 5-year seasoning period, you have a new batch of accessible funds becoming available every year — a "ladder" of conversions providing perpetual access.

Bridge funding: During the first 5 years (while waiting for the ladder to mature), live on Roth IRA contributions (always accessible), taxable brokerage accounts, or the Rule of 55 from your last employer's 401(k).

Common Roth Conversion Mistakes

Paying the tax from the conversion itself: If you convert $100,000 and withhold $22,000 for taxes, only $78,000 goes to your Roth — and the $22,000 withheld is treated as an early distribution with a 10% penalty if you are under 59½. Always pay the tax from a separate account (checking, taxable brokerage) to maximize the Roth balance.

Converting in a high-income year: Converting on top of a $200,000 salary pushes dollars into the 32-35% bracket. Unless you expect even higher rates in the future, wait for a low-income year. The value of Roth conversion depends entirely on paying a lower rate now than you would pay later.

Ignoring state taxes: If you live in a high-tax state now but plan to retire in a no-tax state (Florida, Texas, Nevada), consider waiting to convert until after the move. You could save 5-13% in state income tax on the entire conversion.

Converting too much in one year: A massive single-year conversion can trigger IRMAA (Medicare surcharges lasting 2 years), spike your effective tax rate, and push Social Security into the 85% taxable threshold. Spread conversions over multiple years for optimal tax efficiency.

Frequently Asked Questions

Is a Roth conversion worth it?
Yes if your current tax rate is lower than your expected future rate (including RMDs at 73). A conversion at 12-22% now avoids taxation at 24-32%+ later on decades of growth. The younger you are and the longer the money compounds tax-free, the more valuable the conversion. Model your specific situation with this calculator to see the projected tax savings.
How much should I convert to Roth each year?
Convert enough to fill your current tax bracket without entering the next one. A married couple in the 12% bracket can convert up to the top of the bracket ($96,950 taxable income for 2026). Spreading conversions over 5-10 low-income years is typically more efficient than one large conversion. Account for IRMAA, ACA subsidies, and SS taxation in your calculation.
Do I pay taxes on a Roth conversion?
Yes — the converted amount is added to your taxable income for the year, and you owe federal and state income tax on it. This is the fundamental trade-off: pay taxes now at a known rate for tax-free growth and withdrawals forever. Pay the tax from a separate account, not from the conversion itself, to maximize the Roth balance and avoid early withdrawal penalties.
Can I undo a Roth conversion?
No. Since 2018, Roth conversion recharacterizations (undoing a conversion) are no longer allowed. Once you convert, the tax is owed. This makes it important to model the tax impact carefully before converting and to avoid converting more than your target bracket allows.
What is a Roth conversion ladder?
A strategy for accessing retirement funds before 59½ without penalties. Convert a year's living expenses from Traditional to Roth each year. After each conversion "seasons" for 5 years, the converted principal becomes accessible penalty-free. Used widely by FIRE practitioners to fund early retirement from tax-deferred accounts.
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