{
  "id": "roth-401k",
  "version": "303c353d4e54",
  "status": "published",
  "name": "Roth 401k Calculator",
  "question": "What will my Roth 401(k) be worth?",
  "summary": "Projects a Roth 401(k) balance at retirement within the 2026 IRS contribution limits, and compares it after tax with a traditional 401(k) that costs the same take-home pay.",
  "category": "finance",
  "subcategory": "retirement",
  "url": "https://www.acalculator.org/finance/roth-401k-calculator",
  "markdown": "https://www.acalculator.org/finance/roth-401k-calculator.md",
  "kind": "schedule",
  "method": "Each year: Roth = the lesser of (your % × salary) and your IRS limit (the base limit plus the catch-up for your age); balance = balance × (1 + R) + Roth ÷ 12 × s₁₂, with s₁₂ = R ÷ ((1 + R)^(1/12) − 1). Traditional with the same take-home pay = the lesser of Roth ÷ (1 − tax rate now) and the limit, grown the same way, then × (1 − tax rate in retirement).",
  "assumptions": [
    "The 2026 IRS limits stay the same in later years; employer contributions and the 415(c) total limit are not included.",
    "The return is the same every year. Fees are not included.",
    "Qualified Roth withdrawals are tax-free: you are 59½ or older and the account is at least 5 years old.",
    "The traditional comparison puts in more pre-tax money for the same take-home pay, and taxes all of it at the retirement rate.",
    "This is an estimate for planning, not financial advice."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "age": {
        "title": "Your age now",
        "description": "Your age this year, in whole years.",
        "type": "integer",
        "minimum": 18,
        "maximum": 79
      },
      "retire": {
        "title": "Age you retire",
        "description": "The age you stop contributing. Contributions run until the year before.",
        "type": "integer",
        "minimum": 19,
        "maximum": 80
      },
      "salary": {
        "title": "Salary",
        "description": "Your yearly pay before tax this year.",
        "type": "number",
        "x-unit": "USD",
        "exclusiveMinimum": 0,
        "maximum": 100000000
      },
      "raise": {
        "title": "Yearly raise",
        "description": "How much your salary rises each year.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 20
      },
      "pct": {
        "title": "You put in",
        "description": "Your Roth 401(k) contribution as a percent of your salary, up to the IRS limit.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 100
      },
      "balance": {
        "title": "Roth 401(k) balance now",
        "description": "What is in your Roth 401(k) today.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0,
        "maximum": 10000000000
      },
      "rate": {
        "title": "Yearly return",
        "description": "The yearly return on the account. It stays the same every year.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 30
      },
      "taxnow": {
        "title": "Tax rate now",
        "description": "Your federal and state income tax rate on your last dollar of pay today.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 60
      },
      "taxlater": {
        "title": "Tax rate in retirement",
        "description": "The income tax rate you expect on traditional 401(k) withdrawals in retirement.",
        "type": "number",
        "x-unit": "percent",
        "minimum": 0,
        "maximum": 60
      }
    }
  },
  "outputs": {
    "total": {
      "label": "Your Roth 401(k) at retirement",
      "description": "The balance when you retire: today’s balance, your contributions and their growth. Tax-free when withdrawn as a qualified distribution.",
      "format": "money"
    },
    "contributions": {
      "label": "Your contributions",
      "description": "Everything you put in from now until retirement.",
      "format": "money"
    },
    "growth": {
      "label": "Investment growth",
      "description": "The balance at retirement minus today’s balance and your contributions.",
      "format": "money"
    },
    "yearContribution": {
      "label": "You put in this year",
      "description": "Your Roth contribution this year, after the IRS limit.",
      "format": "money"
    },
    "limit": {
      "label": "Your IRS limit this year",
      "description": "The most you can put in this year at your age: $24,500 plus any catch-up (2026 limits).",
      "format": "money"
    },
    "rothNew": {
      "label": "Roth, new contributions only",
      "description": "What your contributions from now on grow to in the Roth 401(k), after tax (no tax on withdrawal).",
      "format": "money"
    },
    "tradAfter": {
      "label": "Traditional, same take-home pay, after tax",
      "description": "The traditional 401(k) balance from the same take-home pay × (1 − tax rate in retirement).",
      "format": "money"
    },
    "tradBefore": {
      "label": "Traditional balance before tax",
      "description": "The traditional 401(k) balance from the same take-home pay, before tax on withdrawal.",
      "format": "money"
    },
    "rothAhead": {
      "label": "Roth comes out ahead by",
      "description": "Roth (new contributions only) minus traditional after tax. Shown when the Roth is ahead or even (under half a cent behind counts as even).",
      "format": "money"
    },
    "tradAhead": {
      "label": "Traditional comes out ahead by",
      "description": "Traditional after tax minus Roth (new contributions only). Shown when the traditional is ahead.",
      "format": "money"
    },
    "payCap": {
      "label": "Traditional capped at your pay",
      "description": "How many years the traditional contribution for the same take-home pay was cut to 100% of your salary (the annual additions rule). Shown only when it was.",
      "format": "text"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "age": 30,
      "retire": 65,
      "salary": 75000,
      "raise": 3,
      "pct": 10,
      "balance": 0,
      "rate": 7,
      "taxnow": 22,
      "taxlater": 22
    },
    "outputs": {
      "total": 1520981.2182201084,
      "contributions": 453465.6135928812,
      "growth": 1067515.6046272272,
      "yearContribution": 7500,
      "limit": 24500,
      "rothNew": 1520981.2182201084,
      "tradAfter": 1520981.2182201094,
      "tradBefore": 1949975.9207950118,
      "rothAhead": 0
    },
    "text": "Putting 10% of a $75,000.00 salary into a Roth 401(k) from age 30 grows to about $1,520,981.22 by 65."
  },
  "examples": [
    {
      "given": {
        "age": 55,
        "retire": 56,
        "salary": 300000,
        "pct": 20,
        "rate": 0,
        "taxnow": 24,
        "taxlater": 24
      },
      "expect": {
        "yearContribution": 32500,
        "limit": 32500,
        "total": 32500
      },
      "source": "IRS news release IR-2025-111: 2026 limit $24,500, catch-up $8,000 at 50 or older, $11,250 at 60 to 63 (https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500); hand calculation in content.mdx: 20% of 300,000 = 60,000, capped at 24,500 + 8,000"
    },
    {
      "given": {
        "age": 61,
        "retire": 62,
        "salary": 200000,
        "pct": 25,
        "rate": 0,
        "taxnow": 24,
        "taxlater": 24
      },
      "expect": {
        "yearContribution": 35750,
        "limit": 35750
      },
      "source": "IRS news release IR-2025-111: 2026 limit $24,500, catch-up $8,000 at 50 or older, $11,250 at 60 to 63 (https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500); 24,500 + 11,250 = 35,750 at ages 60 to 63"
    },
    {
      "given": {
        "age": 30,
        "retire": 31,
        "salary": 60000,
        "pct": 10,
        "rate": 0,
        "taxnow": 25,
        "taxlater": 25
      },
      "expect": {
        "total": 6000,
        "tradBefore": 8000,
        "tradAfter": 6000,
        "rothAhead": 0
      },
      "source": "IRS news release IR-2025-111: 2026 limit $24,500, catch-up $8,000 at 50 or older, $11,250 at 60 to 63 (https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500); hand calculation in content.mdx: the same take-home pay buys 6,000 ÷ 0.75 = 8,000 pre-tax; 8,000 × 0.75 = 6,000 after tax, equal at equal tax rates"
    },
    {
      "given": {
        "age": 40,
        "retire": 41,
        "salary": 250000,
        "pct": 10,
        "rate": 0,
        "taxnow": 32,
        "taxlater": 32
      },
      "expect": {
        "total": 24500,
        "tradBefore": 24500,
        "tradAfter": 16660,
        "rothAhead": 7840
      },
      "source": "IRS news release IR-2025-111: 2026 limit $24,500, catch-up $8,000 at 50 or older, $11,250 at 60 to 63 (https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500); hand calculation in content.mdx: 24,500 ÷ 0.68 is over the limit, so the traditional also gets 24,500; 24,500 × 0.68 = 16,660"
    },
    {
      "given": {
        "age": 30,
        "retire": 31,
        "salary": 10000,
        "pct": 100,
        "rate": 0,
        "taxnow": 50,
        "taxlater": 50
      },
      "expect": {
        "total": 10000,
        "tradBefore": 10000,
        "tradAfter": 5000,
        "rothAhead": 5000,
        "payCap": "1 year"
      },
      "source": "IRS, Retirement topics: 401(k) and profit-sharing plan contribution limits: no more than 100% of compensation (https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-401k-and-profit-sharing-plan-contribution-limits); hand calculation in content.mdx: 10,000 ÷ 0.5 = 20,000, capped at the 10,000 salary"
    },
    {
      "given": {
        "age": 30,
        "retire": 40,
        "salary": 50000,
        "raise": 0,
        "pct": 12,
        "balance": 10000,
        "rate": 7,
        "taxnow": 22,
        "taxlater": 12
      },
      "expect": {
        "total": 105197.37920096336,
        "contributions": 60000
      },
      "source": "IRS news release IR-2025-111: 2026 limit $24,500, catch-up $8,000 at 50 or older, $11,250 at 60 to 63 (https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500); the same rule and value as the 401(k) calculator’s example ($10,000 at 7% plus $500 a month for 10 years); hand calculation in content.mdx"
    }
  ],
  "sources": [
    "Internal Revenue Service, IR-2025-111 (November 13, 2025): 401(k) limit increases to $24,500 for 2026. https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500",
    "Internal Revenue Service, Roth comparison chart (designated Roth 401(k), Roth IRA and pre-tax 401(k)). https://www.irs.gov/retirement-plans/roth-comparison-chart",
    "Internal Revenue Service, Retirement plans FAQs on designated Roth accounts (qualified distributions). https://www.irs.gov/retirement-plans/retirement-plans-faqs-on-designated-roth-accounts",
    "Federal Register, Catch-Up Contributions, final regulations (September 16, 2025). https://www.federalregister.gov/documents/2025/09/16/2025-17865/catch-up-contributions",
    "Internal Revenue Service, Retirement topics: 401(k) and profit-sharing plan contribution limits (no more than 100% of compensation). https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-401k-and-profit-sharing-plan-contribution-limits"
  ],
  "related": [
    "401k",
    "roth-ira",
    "retirement"
  ],
  "changelog": []
}