FIRE Calculator

On this page, you’ll find a FIRE calculator tool designed to help you forecast when you could realistically reach Financial Independence, Retire Early (FIRE).  It ic compatible with what I call vanilla FIRE, CoastFIRE, or part time work with BaristaFIRE.  This calculator can model different scenarios to see how you could realistically retire and how long it will take.

What does this calculator do?

This FIRE calculator tool takes a few different inputs –  such as  your current portfolio value, annual spending needs, contributions, expected investment returns, and withdrawal rate and runs a projection into the future. It can show you:

• Your FIRE number: the size of your investment portfolio  required to safely support your desired lifestyle using the withdrawal rate you’ve chosen. The Trinity Study suggests this is compsoed of stocks and bonds.
  
  

• Your retirement timeline: based on your savings, contributions, and expected returns, how many years it could take to reach your FIRE number.

• Vanilla FIRE, CoastFIRE or BaristaFIRE:

  • Retire early completely (vanilla FIRE)

  • cease all investment contributions once you’ve reached Coat(CoastFIRE)

  • work part-time/barista income (BaristaFIRE),

The results are illustrative, not financial advice, and as I have advised in My Fire Journey Part 1 see a financial advisor if unsure.

How to use the FIRE calculator

1. Enter your Current  Investment Portfolio

   • This is the total value of your investments that are earmarked for FIRE. Don’t include emergency funds or money for short-term expenses. I would suggest, as mentioned, that these funds are liquid.

2. Annual Spending (today)

3. • Estimate how much you spend per year annually in today’s dollars. This is the lifestyle you want to support in retirement.

   • For accuracy, track your spending for a few months or use last year’s expenses as a baseline.

4. Annual Contributions

   • Enter how much you’re saving and investing toward FIRE each year. For example, if you save $2,000 per month, that’s $24,000 per year.

5. Expected Real Return (%/yr)

   • This is your expected annual investment return after inflation. Many people assume 3–5% real returns for long-term stock/bond portfolios. But some people also assume greater recent performance in the stock market.

   • Being conservative here helps avoid disappointment later.

6. Safe Withdrawal Rate (SWR)

   • Commonly set at 4% as per the Trinity study, this is the percentage of your portfolio you plan to withdraw annually in retirement. Some people prefer 3.5% for safety, others use 4.5% for flexibility. There is some conjecture over the correct figure.

7. Contribution Growth (%/yr)

   • If you expect your income and savings rate to grow each year (say, 2-3%), enter that here. Otherwise leave it at 0. Some people do like to account for inflation.

8. Withdrawal Tax Drag

   • If you’ll pay taxes on withdrawals (depending on your country’s tax rules), you can account for that here as a percentage.

9. Part-time Income in Retirement (BaristaFIRE)

   • Planning to work part-time, consult, or pick up a side gig or pet project during retirement? Enter an estimated annual income here. This lowers the portfolio size you’ll need.

10. Max Years to Simulate

    • Enter how many years you want the calculator to project. For example, 60 years would cover retiring at 40 and living until 100.

11. Click Calculate

    • Once you’ve filled out the inputs, press Calculate to see your results.

How to interpret the results

• Time to FIRE: This shows how many years it will take before your investments reach your FIRE number.

• Portfolio growth projection: You’ll see how your portfolio could grow over time, and when it crosses the “Financial Independence” line.

• Effect of CoastFIRE: If your portfolio is already large enough that it can grow to your FIRE number without further contributions, you’re at CoastFIRE. That means you could stop saving aggressively and simply let compounding do the work.

• Effect of BaristaFIRE: If you add part-time income, you may see your required portfolio shrink. For example, if you need $40,000 per year but plan to earn $10,000 from part-time work, the calculator will adjust your FIRE number downward accordingly.

Tips for using the calculator effectively

• Run multiple scenarios: Adjust your contribution rate, expected returns, or spending to see how sensitive your plan is.

• Test best-case vs worst-case: Try both optimistic and conservative assumptions (e.g., 3% vs 5% returns).

• Revisit inputs yearly: Your income, expenses, or goals may change. Updating your inputs keeps your plan realistic.

• Use it for motivation: Seeing your timeline shrink as you save more or cut expenses can be a powerful motivator to stay on track.

My Final thoughts 

This FIRE calculator tool is meant to be a simple and flexible tool but in saying that, is purely educational. It doesn’t replace professional advice, but it gives you an idea of when you can retire. Whether you are thinking of traditional FIRE (retire decades early, stop working), CoastFIRE (let compounding carry you from here), or BaristaFIRE (part-time work for work/life balance), the FIRE calculator can give you an idea of the years ahead.

Contact me if you have any questions