FIRE Calculator — When Can You Retire Early?

This free FIRE (Financial Independence, Retire Early) calculator estimates the age at which you could reach financial independence. Choose a Lean, Standard, Early-retirement, or Conservative withdrawal model, then enter your current financial situation and an after-inflation real-return assumption to see your projected path in today's dollars.

What is the FIRE Number?

Your FIRE number is the total portfolio size you need to retire. It is calculated as:

FIRE Number = Annual Expenses × Target Multiple

The default Standard FIRE model uses a 4% withdrawal rate and a 25× target multiple (1 ÷ 0.04). Lean FIRE uses 5% and 20×; Early-retirement FIRE uses 3.5% and about 28.6×; Conservative FIRE uses 3% and about 33.3×. These are planning estimates, not guarantees.

Calculator Inputs

Each year the portfolio earns the real return first, then annual income minus annual expenses is added at year end. A positive cash flow is invested; a negative cash flow draws down the projected portfolio. The main chart runs through age 100. CoastFI discounts the same FIRE target back from the selected retirement age and shows how current invested assets would grow with no future contributions. Zero spending is not a meaningful FIRE target, so the calculator asks for annual expenses above zero.

Historical FIRE Analysis methodology

Historical analysis is separate from the deterministic plan. The stock/bond portfolio mix is used only by the Historical FIRE Analysis and Monte Carlo results. It blends U.S. equity and U.S. bond sleeves for those stress tests, but does not change the main deterministic projection, its manually entered expected growth assumption, or the CoastFI estimate. The historical backtest replays every valid rolling sequence in the bundled scenario rows; only the U.S. equity sleeve is observed market history. For the default age-30-through-age-100 scenario, the bundled U.S. history provides 70-year windows with start years from 1926–1955. The seeded bootstrap creates 1,000 synthetic paths by resampling 5-year blocks from the bundled U.S. stock/bond rows; these paths are separate from the rolling backtest. The U.S. equity sleeve uses observed annual real total returns. The U.S. bond sleeve is a modeled long-term government-bond proxy derived from retained FRED yields, a standardized 10-year par-bond pricing convention, and U.S. CPI; pre-2000 LTGOVTBD is not a constant 10-year series. Both sleeves use the common 1926–2024 U.S. CPI/USD-real basis, and the active equity/bond mix is rebalanced annually. The default allocation is 100% U.S. equity and 0% U.S. bonds; other selectable mixes use their active stock/bond allocation rather than assuming every mix is all-equity.

The bundled U.S. equity series is Robert J. Shiller, U.S. Stock Markets data (Yale University). U.S. bonds use a modeled long-term government-bond proxy return constructed from retained FRED LTGOVTBD/GS10 yields and U.S. CPI; FRED publishes raw yields, not total returns, and pre-2000 LTGOVTBD is not a constant 10-year series. A standardized 10-year par-bond pricing convention is used only to model holding-period returns. Both sleeves use the same 1926–2024 U.S. CPI/USD-real basis. Data version 2026-09-04, reviewed 2026-09-04. Scenario results combine observed U.S. equity with a modeled U.S. bond sleeve; they are not forecasts, guarantees, recommendations, or financial advice.

Paths use the selected target multiple, withdrawal rate, income, expenses, and year-end cash-flow convention through age 100. After FI, a path withdraws the target multiplied by the withdrawal rate. The withdrawal rate and target multiple are independent planning assumptions. Success requires reaching FI and being solvent in every evaluated post-FI year through the horizon.

Material limitations remain visible: the tool is not a tax, legal, benefit-entitlement, or investment recommendation. Historical market series are stress tests rather than forecasts.

Learn more with the inflation-adjusted returns guide, compare assumptions in the compound interest calculator, and review our editorial methodology.

Example: Age 30, $100K Net Worth, $90K Income, $50K Expenses, 7% Real Return

With the default Standard FIRE model, a 30-year-old with $100,000 invested, earning $90,000 per year and spending $50,000, invests the $40,000 difference at a 7% after-inflation real return. The FIRE number is $1,250,000 (25 × $50,000), and the portfolio crosses the target at approximately age 45, 15 years away. The projection compounds the balance first and adds the year-end cash flow second.

Frequently Asked Questions

What is the 4% rule?
The 4% rule is a commonly discussed starting point for estimating a portfolio target: annual expenses multiplied by 25. It is a guideline, not a guarantee, and it may not fit every retirement length or portfolio.
What is CoastFI?
CoastFI is the amount you need invested today for your selected FIRE target to grow by your chosen retirement age without future contributions. This view uses the same real-return, annual-expense, and target-multiple assumptions as the main FIRE projection; it is a planning estimate, not a guarantee or personalized advice.
What if I want to retire for 40+ years (early retirement)?
Try the Early-retirement FIRE model at 3.5% or the Conservative FIRE model at 3%. Those settings require roughly 28.6× or 33.3× annual expenses, respectively. A lower withdrawal rate is a more cautious planning assumption, not a guarantee.
What if income is lower than expenses?
The difference is treated as a real annual shortfall and withdrawn from the projected portfolio at year end. If the target is not reached by age 100, the result says so rather than inventing a retirement age.
What return rate should I use?
Use a documented real-return assumption that fits your fees, currency, and time horizon. Historical results are stress tests, not a promised return range.
What is the Historical FIRE Analysis?
The stock/bond portfolio mix is used only by the Historical FIRE Analysis and Monte Carlo results. It blends U.S. equity and U.S. bond sleeves for those stress tests, but does not change the main deterministic projection, its manually entered expected growth assumption, or the CoastFI estimate. The historical backtest replays every valid rolling sequence in the bundled scenario rows; only the U.S. equity sleeve is observed market history. Every mix uses the same 1926–2024 scenario coverage, which provides 70-year windows with start years from 1926–1955 for the default age-30-through-age-100 scenario. The seeded bootstrap separately creates 1,000 derived synthetic paths by resampling aligned 5-year blocks from the bundled scenario rows. The U.S. equity sleeve uses observed annual real total returns. The U.S. bond sleeve is a modeled long-term government-bond proxy derived from retained FRED yields, a standardized 10-year par-bond pricing convention, and U.S. CPI; pre-2000 LTGOVTBD is not a constant 10-year series. Both sleeves use the common 1926–2024 U.S. CPI/USD-real basis, and the active equity/bond mix is rebalanced annually. The observed equity source is Robert J. Shiller, U.S. Stock Markets data (Yale University) (https://www.econ.yale.edu/~shiller/data.htm); retained FRED yield and CPI evidence supports the modeled U.S. bond rows. The result is a stress test, not a forecast. Income and expenses are applied at year end and the post-FI withdrawal is the target multiplied by the withdrawal rate. The target multiple and withdrawal rate are independent planning assumptions. Success requires reaching FI and being solvent in every evaluated post-FI year through age 100.