Retirement · General formulas

Financial Independence / FIRE Age Calculator

Estimate the age when an inflation-adjusted portfolio may reach your spending-based financial independence target using transparent return and contribution assumptions. Use the example values or enter your own numbers to explore an estimate.

Currency formatting only—not an exchange-rate conversion. No country-specific tax or government rules are applied.

Your details

Enter your numbers

USD · example
Additional assumptions in use
  • Effective annual investment return before inflation: 6 %
  • Assumed annual inflation: 2 %
  • Projection horizon: 50 years

Basic mode retains the advanced assumptions shown here. Switching modes does not reset your values.

Values stay in this browser. Saving on this device is optional and requires your consent.

Your results

See a clear estimate

Enter your details to see a personalized calculation, a simple projection, and the assumptions behind it.

Free to use
No sign-up required
Device saving only when requested
FREE TOOLS · NO ACCOUNT

Compare, keep and export

Calculate first to compare a snapshot or export your current results. No values are sent to our server.

The PDF includes active input values and option labels, results, sources, model assumptions, and the schedule when available. Schedule periods follow the model: years, months, or actual payments.

Up to three comparison snapshots

Optional device-only storage

    Share assumptions, never dollar amounts

    Links include eligible rate, term or frequency assumptions only. Dollar amounts are never included. Recipients must enter their own amounts; the link will not reproduce your full financial scenario.

    HOW IT WORKS

    Calculation method

    Divide real annual spending by the user-selected withdrawal fraction to obtain a portfolio target. Convert nominal return and inflation to an exact real return. Grow the portfolio monthly and add one twelfth of the real annual contribution at each month-end. Check the target at each year-end.

    KEEP IN MIND

    Assumptions & limits

    • All monetary projections use today's dollars. Contributions are constant in purchasing power, so their nominal value rises with assumed inflation.
    • No withdrawal rate is endorsed as safe. This is deterministic accumulation math, not a simulation of retirement survival, market volatility, sequence risk, tax or pensions. Age is checked at year-end; target attainment can later reverse under negative returns.
    • Basis: User-entered spending, inflation, return and withdrawal assumptions.
    • Basis: https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator.

    Source/rule review year: Not applicable — general mathematical model.

    FIRE ACCUMULATION WORKED EXAMPLE

    An accumulation target under stated assumptions.

    Fictional inputs: age 34, invested balance $125,000, annual contribution $18,000 in today's dollars, annual spending target $45,000, a user-selected 4% target withdrawal fraction, 6% nominal annual return, and 2% inflation.

    Illustrative values calculated using this page’s calculator definition · USD display, no conversion
    PartItemValue
    InputCurrent age34 years
    InputCurrent invested portfolioUSD 125,000.00
    InputAnnual contribution in today's dollarsUSD 18,000.00
    InputAnnual retirement spending in today's dollarsUSD 45,000.00
    InputTarget withdrawal percentage (not guaranteed)4 %
    InputEffective annual investment return before inflation6 %
    InputAssumed annual inflation2 %
    InputProjection horizon50 years
    ResultModeled FIRE age60 years
    ResultFIRE target in today's dollarsUS$1,125,000.00
    ResultAssumed annual real return3.9%
    ResultYears to modeled target26 years
    ResultPortfolio at horizon in today's dollarsUS$3,585,537.81

    How to interpret it

    The target portfolio is derived from today's-dollar spending divided by the selected withdrawal fraction. The calculator converts the nominal return and inflation to a real rate, grows the portfolio monthly, adds one-twelfth of the inflation-adjusted annual contribution at month-end, then checks the target at each year-end. The selected fraction is an input, not a safe-withdrawal recommendation.

    Limits of this example

    • This is accumulation math only: it does not simulate retirement withdrawals, portfolio survival, market volatility, or sequence-of-returns risk.
    • No pension, tax, account rules, or government benefits are included. The real contribution is assumed constant in purchasing power; a later negative-return path could reverse a prior target crossing.

    Possible next steps

    Financial Independence / FIRE Age Calculator | WealthMathPro