Plan your journey to financial independence with our comprehensive FIRE calculator. Discover your FI number, estimate your retirement age based on your savings rate, and learn which FIRE strategy fits your lifestyle — whether it's Lean, Coast, Barista, or Fat FIRE.
These examples use the same formulas as the calculator above. Try loading any example to verify the math.
Age 30 with $40,000 annual expenses, $100,000 saved, saving $40,000/year (50% savings rate), 7% return. FIRE Number = $1,000,000 (40k × 25). Years to FI ≈ 15–18, FI Age ≈ 45–48.
Age 25 with $60,000 annual expenses, $50,000 saved, saving $40,000/year (40% savings rate), 7% return. FIRE Number = $1,500,000. Years to FI ≈ 25–30, FI Age ≈ 50–55.
Age 22 with $25,000 annual expenses, $10,000 saved, saving $37,500/year (60% savings rate), 7% return. FIRE Number = $625,000. Years to FI ≈ 12–14, FI Age ≈ 34–36.
Lean FIRE prioritizes extreme frugality to reach financial independence quickly. Typically requires living on a modest budget in a low-cost area. Best suited for minimalists who value time over material possessions.
Coast FIRE means you've saved enough that compound interest will grow your investments to your full FIRE number by traditional retirement age (65). You still work to cover current expenses but no longer need to save for retirement — the market does the work for you.
Barista FIRE involves semi-retirement with part-time work covering a portion of expenses. Named after the idea of working a low-stress job (like a barista) that provides health insurance and supplemental income while your investments cover the rest.
Fat FIRE targets a higher standard of living in retirement. No strict budgeting, luxury travel, fine dining, and expensive hobbies are all on the table. Requires a significantly larger nest egg and usually a higher income career path.
Our calculator uses the 4% withdrawal rule validated by the Trinity Study, which found a 95%+ success rate for 30-year retirements using a 60/40 stock/bond portfolio.
Uses the time value of money formula to project how your current savings and annual contributions will grow with compound returns, giving you a realistic FI timeline.
Automatically classifies your results into Lean, Coast, Barista, or Fat FIRE categories so you can see which financial independence path aligns with your numbers.
Understand how increasing your savings rate dramatically reduces your years to FI — every percentage point brings you weeks closer to financial independence.
FIRE stands for Financial Independence, Retire Early. It is a lifestyle and savings movement focused on aggressively saving and investing a large portion of your income — typically 50% to 70% — so you can achieve financial independence decades earlier than the traditional retirement age of 65. The core idea is simple: once your investment portfolio generates enough passive income to cover your annual living expenses, you have the option to retire early or pursue work on your own terms.
The FIRE movement gained mainstream traction in the 2010s, popularized by blogs, books like Your Money or Your Life by Vicki Robin, and communities like r/financialindependence on Reddit. The central calculation relies on the 4% rule from the Trinity Study, which suggests that withdrawing 4% of your portfolio's initial value each year (adjusted for inflation) has a very high probability of lasting through a 30-year retirement.
Mathematically, your FIRE Number equals your annual expenses divided by your chosen withdrawal rate. At a 4% withdrawal rate, this simplifies to Annual Expenses × 25. For example, if you spend $40,000 per year, your target nest egg is $1,000,000. The number of years needed to reach that goal depends on your current savings, annual contributions, and expected investment returns using the future value of a series formula.
| Withdrawal Rate | Success Rate (30 years) | Success Rate (40 years) | FIRE Number Multiplier |
|---|---|---|---|
| 3.0% | ~99% | ~97% | 33.3× expenses |
| 3.5% | ~98% | ~93% | 28.6× expenses |
| 4.0% | ~95% | ~85% | 25× expenses |
| 5.0% | ~85% | ~70% | 20× expenses |
| 6.0% | ~70% | ~50% | 16.7× expenses |
Source: Trinity Study (Bengen, 1994) and subsequent updates by Pfau, Kitces, and others. Data shown is for a 60/40 stock/bond portfolio.
The 4% rule is the foundation of the FIRE movement. Developed by financial advisor William Bengen in 1994 and later validated by the Trinity Study (Cooley, Hubbard, and Walz), the rule states that withdrawing 4% of your initial portfolio value in your first year of retirement, then adjusting that dollar amount for inflation each subsequent year, gives you a 95%+ probability of your portfolio lasting at least 30 years.
For FIRE followers planning 40–60 year retirements, the 4% rule may be too aggressive. Many experts recommend a 3.5% or even 3% withdrawal rate for longer time horizons. The chart below shows how your withdrawal rate changes the size of the nest egg you need:
Historical S&P 500 returns average approximately 10% per year before inflation and roughly 7% after adjusting for 2–3% inflation. Using a conservative expected return of 7% in your projections provides a realistic estimate of your FIRE timeline. Remember that sequence-of-returns risk — experiencing a market downturn early in retirement — is the biggest threat to your portfolio's longevity, which is why the withdrawal rate matters so much.
Answers to common questions about the FIRE movement and how our calculator works.
This FIRE calculator provides estimates based on mathematical models and historical return data. It does not constitute financial advice. Actual investment returns vary, and past performance does not guarantee future results. Sequence-of-returns risk, inflation, taxes, healthcare costs, and lifestyle changes can significantly impact your FIRE timeline. Always consult a qualified financial advisor before making retirement decisions. The Trinity Study data shown reflects historical US stock and bond market performance.