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How to Use the FIRE Calculator

 

This guide walks you through each step and input in the FIRE Calculator (with Barista FIRE Options). By the end, you’ll know how to configure your parameters, run a projection, and interpret the results.

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1. Accessing the Calculator​

  1. You’ll see a form divided into logical sections:

    • Personal & Investments

    • Returns & Inflation

    • Home Sale

    • Expenses & Income

    • Barista Income & Duration

    • Social Security & Pension

    • Custom FIRE Stage Ages
       

2. Entering Personal & Investment Data

  • Current Age: Your age today (e.g. 30).

  • Life Expectancy: The age until which you want to project your portfolio (e.g. 90).

  • Current Portfolio (€): The amount you have saved/invested now.

  • Lump Sum (€): A one‑time or repeated contribution (next field).

  • Lump Frequency:

    • Once — adds the lump sum immediately and no more.

    • Yearly — adds the lump sum at the end of each accumulation year.

  • Monthly Contribution (€): Fixed monthly savings amount.

  • Annual Increase of Monthly Contributions (%): Year‑over‑year growth rate applied to your monthly contribution (e.g. 2% per year).

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3. Configuring Returns & Inflation

  • Build‑up Return (%): Annualized growth rate during the accumulation phase (before FIRE).

  • Harvest Return (%): Expected return once you’ve reached FIRE and begin withdrawals.

  • Inflation Rate (%): Annual inflation used to adjust withdrawals, social pensions, etc.
     

4. Projecting Home Sale

  • Home Sale Value (€): Estimated selling price of your home.

  • % Reinvest: Portion of sale proceeds you’ll reinvest into your portfolio.

  • Home Sale in (yrs): Number of years from your current age when the sale occurs.
     

5. Defining Expenses & Income Sources

  • Fixed Costs (€): Essential expenses you withdraw monthly/annually (e.g. mortgage, utilities).

  • Living Costs (€): Day‑to‑day living expenses (food, transport).

  • Luxury Costs (€): Discretionary spending (travel, hobbies).

  • Barista Income (€) & Duration (yrs): Part‑time earnings and how many years you plan to work post‑FIRE.
     

6. Social Security & Pension

  • Social Security (€) & Start Age: Annual government benefits and the age you begin collecting them.

  • Pension Income (€) & Start Age: Company or private pension income and its start age.
     

7. Custom FIRE Stage Ages

  • Lean FIRE Age: Age when you enter lean–FIRE (minimal withdrawals to cover fixed costs).

  • Full FIRE Age: Age when you ramp up to cover fixed + living costs.

  • Fat FIRE Age: Age when you plan to cover all expenses (fixed + living + luxury).
     

8. Running the Calculation

  1. After filling all inputs, click Calculate.

  2. The calculator will:

    • Accumulate savings until the latest of your three FIRE ages (with annual/monthly contributions & lumps).

    • Simulate portfolio growth and withdrawals with barista income, social security, and pension after each stage.
       

9. Interpreting the Results

  • Remaining at [Life Expectancy]:

    • Lean FIRE: Portfolio balance if you retired at your Lean FIRE age.

    • Full FIRE: Balance retiring at your Full FIRE age.

    • Fat FIRE: Balance retiring at your Fat FIRE age.

  • Chart: A line graph showing portfolio value over time for each stage.
     

10. Tips & Tricks

  • Experiment with different annual increases to see how modest raises accelerate your fire date.

  • Adjust build‑up vs. harvest returns for conservative vs. aggressive scenarios.

  • Revisit inputs annually—update your actual portfolio, contributions, or age.

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