Calculate your financial independence number, time to FIRE, and required savings rate with lean, regular, and fat FIRE scenarios.
The FIRE Calculator centers financial independence on three versions of retirement spending: lean, regular, and fat FIRE. It relates each budget to a financial independence number, then compares that target with current finances and saving assumptions to estimate when the target could be reached and what savings rate would be required. The common surprise is that the scenario name does not determine the answer by itself. Annual spending and the withdrawal-rate assumption drive the portfolio target, while investment growth and contributions drive the timeline.
For a chosen scenario, annual spending is converted into the portfolio needed to support that spending using the applicable withdrawal rate. The relationship is annual spending divided by withdrawal rate. At any fixed budget, a smaller withdrawal rate means a larger FIRE number. Lean, regular, and fat results differ because they represent different annual spending assumptions.
The time-to-FIRE estimate relates current investable assets, future savings, and assumed investment growth to the selected FIRE number. The required savings rate presents the contribution burden relative to income under the same plan assumptions. The two figures answer different questions: one reports how long the assumed path takes, while the other reports how much income must be saved.
Retirement spending is recurring, so the withdrawal-rate calculation turns every additional annual dollar into a larger portfolio requirement. The same spending increase creates a larger target increase when the withdrawal rate is lower. Read the displayed FIRE number as conditional on both the selected scenario budget and withdrawal assumption, not as a fixed valuation of your needs.
No. It estimates whether the entered assets, savings, spending, and growth assumptions reach a mathematical target. It cannot guarantee future returns or determine whether the plan covers taxes, health care, emergencies, changing expenses, or longevity. Before acting, test less favorable assumptions and review income sources and risks that are not represented in the calculation.
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