{
  "slug": "roth-conversion-calculator",
  "title": "Roth Conversion Calculator — Tax Cost and Break-Even (2026)",
  "heading": "Roth Conversion Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/roth-conversion-calculator",
  "summary": "See what converting traditional IRA dollars to Roth costs in tax today, how much bracket headroom you have, and when the conversion pays for itself.",
  "description": "A Roth conversion moves money from a pre-tax IRA into a Roth, triggering ordinary income tax now in exchange for tax-free growth later. Whether it's a win comes down to two numbers: your rate today versus your rate when you'd otherwise withdraw. This calculator shows the tax bill, the bracket you'd land in, how much you could convert without crossing into the next bracket, and the year the conversion breaks even.",
  "formula": "Conversion tax = federal tax on (other income + conversion) − federal tax on other income alone. Roth path = converted principal × (1 + return)^years. Traditional path = conversion × (1 + return)^years × (1 − future tax rate), plus the after-tax growth of the dollars you didn't spend on tax.",
  "dateModified": "2026-08-31",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=roth-conversion-calculator",
  "inputs": [
    {
      "id": "convert",
      "label": "Amount to convert",
      "kind": "number",
      "hint": null,
      "default": 60000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "otherIncome",
      "label": "Your other taxable income",
      "kind": "number",
      "hint": null,
      "default": 70000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "status",
      "label": "Filing status",
      "kind": "select",
      "hint": null,
      "default": "married",
      "options": [
        {
          "value": "single",
          "label": "Single"
        },
        {
          "value": "married",
          "label": "Married filing jointly"
        }
      ]
    },
    {
      "id": "futureRate",
      "label": "Expected tax rate in retirement",
      "kind": "number",
      "hint": null,
      "default": 24,
      "unit": "%",
      "min": 0,
      "max": 50
    },
    {
      "id": "growth",
      "label": "Assumed annual return",
      "kind": "number",
      "hint": null,
      "default": 6.5,
      "unit": "%",
      "min": -10,
      "max": 20
    },
    {
      "id": "years",
      "label": "Years until you'd withdraw",
      "kind": "number",
      "hint": null,
      "default": 15,
      "unit": null,
      "min": 1,
      "max": 50
    },
    {
      "id": "payFromOutside",
      "label": "How will you pay the conversion tax?",
      "kind": "select",
      "hint": null,
      "default": "outside",
      "options": [
        {
          "value": "outside",
          "label": "From taxable savings (better)"
        },
        {
          "value": "inside",
          "label": "Withhold it from the conversion"
        }
      ]
    }
  ],
  "outputs": [
    {
      "id": "tax",
      "label": "Federal tax on the conversion",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "effective",
      "label": "Effective rate on converted dollars",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "marginal",
      "label": "Marginal bracket after converting",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "headroom",
      "label": "Room left in your current bracket",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "rothFuture",
      "label": "Roth value at withdrawal",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "tradFuture",
      "label": "After-tax value if you don't convert",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "advantage",
      "label": "Conversion advantage",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "verdict",
      "label": "Verdict",
      "format": "raw",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Amount to convert: 60000 $",
      "Your other taxable income: 70000 $",
      "Filing status: Married filing jointly",
      "Expected tax rate in retirement: 24 %",
      "Assumed annual return: 6.5 %",
      "Years until you'd withdraw: 15",
      "How will you pay the conversion tax?: From taxable savings (better)"
    ],
    "outputs": [
      "Federal tax on the conversion: $7,505.00",
      "Effective rate on converted dollars: 12.51%",
      "Marginal bracket after converting: 22%",
      "Room left in your current bracket: $56,950.00",
      "Roth value at withdrawal: $154,310.46",
      "After-tax value if you don't convert: $134,090.34",
      "Conversion advantage: $20,220.12",
      "Verdict: Converting wins at these assumptions"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter amount to convert ($).",
      "Enter your other taxable income ($).",
      "Enter filing status.",
      "Enter expected tax rate in retirement (%).",
      "Enter assumed annual return (%).",
      "Enter years until you'd withdraw.",
      "Enter how will you pay the conversion tax?.",
      "Read your federal tax on the conversion on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Gap-year conversion",
      "values": {
        "convert": 60000,
        "otherIncome": 30000,
        "status": "married",
        "futureRate": 24,
        "years": 12
      }
    },
    {
      "name": "Fill the 22% bracket",
      "values": {
        "convert": 100000,
        "otherIncome": 95000,
        "status": "married",
        "futureRate": 24,
        "years": 15
      }
    },
    {
      "name": "High earner, skeptical",
      "values": {
        "convert": 50000,
        "otherIncome": 240000,
        "status": "single",
        "futureRate": 22,
        "years": 10
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "When does a Roth conversion make sense?",
      "a": "When your tax rate today is lower than the rate you expect when the money comes out. That's usually true in the gap years between retiring and starting Social Security or RMDs, in a year with unusually low income, or if you expect large RMDs to push you into a higher bracket later."
    },
    {
      "q": "How is a Roth conversion taxed?",
      "a": "The converted amount is added to your ordinary income for the year. There is no early-withdrawal penalty on a conversion regardless of age, but each conversion carries its own five-year clock before the converted principal can be withdrawn penalty-free if you're under 59½."
    },
    {
      "q": "Should I pay the conversion tax from the IRA itself?",
      "a": "Almost never, if you can avoid it. Withholding the tax from the conversion shrinks the amount that lands in the Roth and, under 59½, the withheld portion is treated as a taxable distribution with a penalty. Paying from taxable savings is materially better."
    },
    {
      "q": "Does a Roth conversion affect Medicare premiums?",
      "a": "Yes. Conversion income counts toward modified adjusted gross income for IRMAA, which is assessed on a two-year lookback. A large conversion at 63 or later can raise Medicare Part B and D premiums, so many people convert in slices to stay under the brackets."
    },
    {
      "q": "Is there a limit on how much I can convert?",
      "a": "No dollar limit and no income limit. You can convert any amount in any year. The practical limit is the tax bracket you're willing to fill — which is why converting to the top of a bracket, rather than all at once, is the common strategy."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/rmd-calculator",
    "https://www.revenuelab.fyi/toolbox/retirement-withdrawal-calculator",
    "https://www.revenuelab.fyi/toolbox/inherited-ira-rmd-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Roth Conversion Calculator — Tax Cost and Break-Even (2026) (https://www.revenuelab.fyi/toolbox/roth-conversion-calculator)"
}