FIRE Calculator - Find Your Financial Independence Number
This calculator computes your Financial Independence number across 6 retirement strategies by applying the 4.0% safe withdrawal rate (Trinity Study, 1998) and compound interest projections to your annual expenses, current savings, and investment timeline.
Financial Details
Your investing strategy
Advanced Settings & Pro Features
Results
Your FIRE Timeline
Projected wealth growth from your current age to retirement
What is included in my FIRE Number breakdown?
Financial independence projections vary across retirement strategies based on annual spending targets and asset allocation. Your FIRE Number breakdown calculates the specific portfolio requirements for Traditional, Lean, Fat, Coast, Barista, and Flamingo FIRE scenarios using real-time math.
How are these numbers calculated?
Traditional FIRE
Your portfolio fully replaces earned income. Formula: Annual Spending ÷ 0.04 = Target. At $60,000 spending the target is $1,500,000. No part-time income bridge required — the 4% Safe Withdrawal Rate funds all expenses indefinitely.
Coast FIRE
Invest enough today so compound growth alone reaches your Traditional FIRE target by retirement age — no further contributions needed. Formula: Target ÷ (1 + real return)^years. The earlier you start, the smaller this number.
Lean FIRE
Applies the 25× rule to minimalist spending capped at $40,000/year. Formula: min(Spending, $40,000) × 25. At $30,000 annual spend the target is $750,000 — reachable years earlier than Traditional FIRE through deliberate expense reduction.
Fat FIRE
Applies the 25× rule to comfort spending of $100,000+ per year. Formula: max(Spending, $100,000) × 25. At $120,000 annual spend the target is $3,000,000. The larger portfolio provides greater resilience against market downturns and inflation.
Barista FIRE
Portfolio covers 60% of expenses — a part-time job bridges the remaining 40%. Formula: Spending × 0.60 × 25. At $60,000 annual spend the portfolio target is $900,000 instead of the full $1,500,000 Traditional number.
Flamingo FIRE
Save exactly 50% of your Traditional FIRE number then stop all contributions. Formula: Spending × 0.50 × 25. The Rule of 72 predicts this portfolio doubles in ~10 years at 7.2% real return, delivering full financial independence.
What is a FIRE number and how do I calculate it?
Your FIRE number is your total portfolio target (the amount at which your investments permanently replace your salary). The formula is: Annual Expenses / Safe Withdrawal Rate = FIRE Number. At the default 4% withdrawal rate, spending $40,000 per year means you need a $1,000,000 portfolio.
That formula comes from two peer-reviewed studies: William Bengen’s 1994 analysis of 50 years of U.S. market data (Journal of Financial Planning) and the 1998 Trinity Study (Cooley, Hubbard & Walz). Both confirmed that a 4% annual withdrawal from a diversified stock-and-bond portfolio survived every 30-year retirement window in the historical record.
You have 3 levers (and you control all of them):
- Cut your annual spending – Every $1,000 you remove from your yearly budget reduces your FIRE number by $25,000 at a 4% withdrawal rate. This lever is faster than earning more.
- Raise your savings rate – The percentage of income you invest each month is the single biggest driver of how quickly you close the gap.
- Set your withdrawal rate – The longer your retirement needs to last, the lower this number should go. More on this in the SWR section below.
What are the 6 types of FIRE?
The 6 FIRE strategies are not competing ideologies (they are different answers to the same question: how much work flexibility do you want, and how soon?). Each type produces a different target number, a different timeline, and a different relationship with part-time income during retirement.
Use the 2-sentence summaries below to orient yourself, then click through to the dedicated calculator for the strategy that fits your situation.
Traditional FIRE
You build a full portfolio (25x your annual expenses) and stop working entirely. This is the baseline every other strategy is compared against.
Learn what a FIRE number isLean FIRE
You retire early on a deliberately minimal budget, typically under $40,000 per year for a single person. Your required portfolio is smaller, but your margin for unexpected costs: a medical event, a market crash, an inflation spike: is thinner.
Find your Lean FIRE numberFat FIRE
You retire with a $100,000+ annual budget, maintaining a lifestyle close to your working years. The larger portfolio required makes this strategy more resilient to market downturns, but the accumulation phase is longer.
Build your Fat FIRE projectionCoast FIRE
You invest aggressively early, hit a specific “Coast Number,” then stop contributing and let compound interest carry your portfolio to your Traditional FIRE target by retirement age. Our Coast FIRE tool calculates the exact dollar amount your portfolio needs to reach today so that compounding does the rest without another cent from you.
Find your Coast FIRE numberBarista FIRE
You partially retire, using a small part-time income to cover current living expenses while your invested portfolio compounds untouched. The Barista FIRE calculator accounts for part-time hourly wage, weekly hours, and the dollar value of employer-provided health insurance: inputs this master calculator does not model at that level of detail.
Model your Barista FIRE income gapFlamingo FIRE
You accumulate exactly 50% of your Traditional FIRE number, then stop all contributions. Compound interest doubles the portfolio over time. Historically, assuming a 7.2% average real return, this takes approximately 10 years (using the Rule of 72: 72 / 7.2 = 10), though actual timelines will vary based on market volatility.
Run your Flamingo FIRE projectionWhich FIRE strategy fits my situation?
The right strategy is the one whose target number and work requirements match your life (not the one with the most aggressive timeline). The table below maps each strategy against its spending level, required portfolio, and the degree of work it demands after you leave your primary career.
| Strategy | Annual Spend | Target Portfolio (4% SWR) | Work After FIRE? | Best Fit |
|---|---|---|---|---|
| Lean FIRE | Under $40K | Under $1M | None | Minimalist lifestyle; low cost-of-living area |
| Traditional FIRE | $40K-$80K | $1M-$2M | None | Standard full early retirement |
| Fat FIRE | $100K+ | $2.5M+ | None | Maintaining current lifestyle in retirement |
| Coast FIRE | Any | Partial (Coast Number) | Full-time until Coast Number hit | Savers who genuinely like their work |
| Barista FIRE | Any | Partial + part-time income | Part-time (health insurance is the priority) | Ages 45-64 bridging the pre-Medicare gap |
| Flamingo FIRE | Any | 50% of FIRE Number | Full-time until halfway point | Investors who want to front-load contributions |
Use the Strategy Comparison tab in the calculator above to run all 6 numbers side-by-side on your inputs.
How much does my savings rate actually matter?
Your savings rate (the percentage of take-home income you invest each month) is the most powerful lever you have. Nothing else comes close.
Assuming a starting net worth of zero, a 7% real annual return, and $80,000 of after-tax take-home pay, here is what savings rate does:
| Savings Rate | Annual Amount Invested | Years to FIRE |
|---|---|---|
| 10% ($8,000/yr) | Spending $72,000 | ~43 years |
| 25% ($20,000/yr) | Spending $60,000 | ~32 years |
| 50% ($40,000/yr) | Spending $40,000 | ~17 years |
| 75% ($60,000/yr) | Spending $20,000 | ~7 years |
(This model uses an optimistic 7% real accumulation rate. Mr. Money Mustache’s original 2012 analysis assumed a more conservative 5% real return (the Advanced Settings let you test both).)
The reason cutting expenses beats earning more is mathematical: lower spending simultaneously reduces your FIRE number and frees up more capital to invest every month. A $500/month expense cut does both jobs at once.
What Safe Withdrawal Rate should I use?
The short answer: 4.0% if you are retiring at 60+. 3.25%-3.5% if you are retiring before 50. (For ultra-early retirees under 40 facing a 50+ year horizon, many conservative planners use a 3.0% floor.)
This calculator defaults to 4.0% because it matches the Bengen and Trinity Study benchmark: the most widely cited number in retirement research. But that research modeled 30-year retirements. If you are 35 and plan to retire at 45, your portfolio needs to fund 50+ years, and 4.0% carries meaningful failure risk for that window.
To adjust for a longer horizon: open Advanced Settings and lower your SWR. At 3.25%, a $40,000 annual spend requires a $1,230,769 portfolio: roughly $231,000 more than the 4% baseline. That extra cushion exists for three reasons:
- Sequence of Returns Risk: A major market decline in years 1-5 of retirement can permanently damage a portfolio, even if long-term average returns recover. This is the primary risk for early retirees, not average market performance.
- Longevity Risk: The 4% rule was not stress-tested against 50-year retirements. A portfolio that survives 30 years may deplete before a 50-year window ends.
- Healthcare cost inflation: Pre-Medicare health insurance (ages 45-64) inflates faster than general CPI. ACA premiums average $650-$900/month per person at age 55, before subsidies (Kaiser Family Foundation, 2024).
How does this calculator handle inflation?
By default, every figure uses real returns: portfolio values expressed in today’s purchasing power, with inflation already subtracted. A projected number of $1,200,000 in this mode means $1,200,000 in today’s dollars, not the inflated dollar of 30 years from now.
Switching to Future Dollars (the Advanced Settings toggle) shows nominal returns: the raw account balance you will see in your brokerage statement. That number is larger, but it overstates your actual purchasing power.
Why 2022 changed the calculus: The 2021-2023 inflation cycle peaked at 9.1% CPI in June 2022: the highest reading in 40 years. A retiree who left work in January 2022 absorbed a market drawdown and purchasing power erosion at the same time. That is the scenario the Inflation Rate slider exists to stress-test. Pull it to 4.0%-4.5% and watch what happens to your FIRE number. The default 3.0% assumption has not aged well.
Where does this calculator’s math come from?
Every projection uses three evidence-based foundations: the 4% rule, real-return compounding, and Monte Carlo simulation. None of them are invented by this tool.
The 4% Rule: Bengen (1994) and the Trinity Study (Cooley, Hubbard & Walz, 1998) both tested annual 4% withdrawals from a diversified portfolio against every rolling 30-year window of U.S. market history since 1926. The 4% rate survived 95%+ of scenarios on a 50/50 stock-bond allocation.
Real Returns: The default projection subtracts a 3.0% inflation rate from a 7.0% nominal market return, producing a 4% real return. The Advanced Settings sliders let you change both variables independently. All displayed dollar figures reflect today’s purchasing power unless you enable the Future Dollars toggle.
Monte Carlo Simulation: The calculator runs 10,000 randomized return sequences drawn from historical volatility data. The output: your portfolio survival percentage shows how many of those 10,000 scenarios ended with money still in your account. A survival rate of 90%+ reflects a historically sound plan; below 80% suggests raising your target or extending your timeline. These simulations assume no behavioral adaptation (no spending cuts in downturns, no part-time income), which makes them deliberately conservative.
What are the real risks to a FIRE plan?
Every FIRE plan carries four risks. Three of them appear in every calculator. One (modern inflation) most calculators still underweight. The Advanced Settings exist specifically to let you stress-test all four.
1. Sequence of Returns Risk (SORR)
Plain English: a bad market at the worst possible time.
A 30-40% market decline in years 1-5 of retirement can permanently impair your portfolio, even if the market fully recovers later. Use the SORR toggle in Advanced Settings to model a bear market in the first 3 years of your projection and see what it does to your survival rate.
2. Healthcare Cost Risk (Pre-Medicare)
Plain English: health insurance is expensive, and nobody warns you how expensive.
Before Medicare at 65, you pay the full cost of private health insurance. ACA Silver plan premiums average $650-$900/month per person at age 55, before income-based subsidies (Kaiser Family Foundation, 2024). This is the single most underestimated cost in early retirement. The Barista FIRE calculator models this gap directly.
3. Longevity Risk
Plain English: you might live longer than your model assumes.
A 35-year-old retiring today could live 55 more years. The 4% rule was never tested against 55-year retirement windows. Use a 3.25% SWR if your planned retirement horizon exceeds 40 years.
4. Modern Inflation Risk
Plain English: the 3% historical average is no longer a safe assumption.
The 2022-2023 inflation spike showed that CPI can hit 8-9% in a supply-disrupted economy. At 4% sustained inflation instead of 3%, a $1,000,000 portfolio loses approximately $87,000 in additional real purchasing power over 30 years: that is not a rounding error. Stress-testing against 4.0%-4.5% inflation in your projection is now standard due diligence, not pessimism.
Frequently Asked Questions
What is a FIRE number?
What is the 4% rule in plain English?
How long does it take to reach FIRE?
Is the 4% rule safe for early retirees?
What is the difference between Coast FIRE and Barista FIRE?
What is Flamingo FIRE?
Ready to find your exact timeline? Scroll back to the top to run your numbers through the calculator, or choose a specific FIRE strategy above to dive deeper.