FIRE Calculator — Financial Independence & Early Retirement

Calculate when you can achieve financial independence and retire early. Find your FI number, see your timeline, and compare different FIRE strategies.

How to Use This FIRE Calculator

  1. Enter your annual income — Your total pre-tax household income.
  2. Enter your annual expenses — What you spend per year (the lower this is, the faster you reach FIRE).
  3. Enter your current savings — Total invested assets you already have.
  4. Set your expected return — Historical stock market average is ~7% after inflation.
  5. Set inflation rate — Historical average is ~3%.
  6. Click Calculate — See your FI number, timeline, and year-by-year projection.

What Is FIRE?

FIRE stands for Financial Independence, Retire Early. It's a movement built around the idea that by saving a much higher percentage of your income (typically 50%+), you can achieve financial independence and retire decades earlier than the traditional age of 65.

The core principle is simple: the more you save, the less you need to live on, and the faster your investments grow. This creates a double benefit — you save more money each year AND your target number is lower because your expenses are lower.

The 4% Rule

The FIRE movement is built on the 4% rule (also called the Trinity Study). It states that if you withdraw 4% of your portfolio in the first year of retirement, and adjust that amount for inflation each subsequent year, your portfolio has a very high probability of lasting 30+ years.

FI Number = Annual Expenses × 25
(Because 1 / 0.04 = 25)

For example, if you spend $40,000 per year, your FI number is $1,000,000. Once you have $1M invested, you can theoretically live off 4% withdrawals indefinitely.

Types of FIRE

  • Lean FIRE: Living on less than $40,000/year. Requires a smaller portfolio (~$1M or less) but means a more frugal lifestyle.
  • Regular FIRE: Living on $40,000-$100,000/year. The middle ground that most FIRE seekers target.
  • Fat FIRE: Living on $100,000+/year. Requires a larger portfolio ($2.5M+) but maintains a comfortable lifestyle.
  • Barista FIRE: Reaching enough savings to cover most expenses, but working part-time for supplemental income and health insurance.
  • Coast FIRE: Having enough saved that you don't need to contribute more — just let compounding grow it to your FI number by traditional retirement age.

How Savings Rate Affects Your FIRE Timeline

Your savings rate is the single most important factor in how quickly you reach FIRE:

  • 10% savings rate: ~51 years to FIRE
  • 25% savings rate: ~32 years to FIRE
  • 50% savings rate: ~17 years to FIRE
  • 65% savings rate: ~10 years to FIRE
  • 75% savings rate: ~7 years to FIRE

This assumes a 5% real return (after inflation). The math is powerful — going from 10% to 50% savings rate cuts your working years from 51 to 17, a reduction of 34 years!

FIRE Calculation Formula

Our calculator uses a year-by-year simulation that accounts for:

  • Annual savings from income minus expenses
  • Investment growth at your expected return rate
  • Inflation impact on expenses (your FI number grows with inflation)
  • Income and expense growth over time
Each Year:
  Savings = Income × (1 + incomeGrowth) - Expenses × (1 + inflationRate)
  Portfolio = (Previous Portfolio + Savings) × (1 + returnRate)
  FI Number = Expenses × (1 + inflationRate)^Year × 25
  FIRE achieved when Portfolio ≥ FI Number

Frequently Asked Questions

Is the 4% rule still valid in 2025?
The 4% rule is based on historical U.S. data from 1926-2020. Recent studies suggest it still works for 30-year retirements, but for early retirees (who may need 40-60 years of withdrawals), a more conservative 3.5% or 3% withdrawal rate may be safer. This would make your FI number = expenses × 28.6 or × 33.3 instead of × 25.
What if the market crashes right after I retire?
This is called sequence of returns risk, and it's the biggest risk for early retirees. If the market drops significantly in your first few years of retirement while you're withdrawing money, your portfolio may never recover. Mitigation strategies include: keeping 2-3 years of expenses in cash/bonds, reducing withdrawals during downturns, having a cash buffer, or maintaining a barista FIRE approach with some part-time income.
Does FIRE account for taxes?
This calculator uses pre-tax income and estimates. In practice, you'll need to account for: income taxes on withdrawals from traditional accounts, capital gains taxes on taxable accounts, and potentially state taxes. Roth accounts can be withdrawn tax-free in retirement. Many FIRE retirees strategically manage their withdrawal sources to minimize taxes.
What about health insurance before Medicare?
Health insurance is one of the biggest challenges for early retirees. Options include: ACA marketplace plans (with subsidies based on income), COBRA continuation, health sharing ministries, or part-time work that provides coverage. Many FIRE retirees keep their income low enough to qualify for substantial ACA subsidies.
How much should I have saved by 30, 35, 40 for FIRE?
It depends entirely on your expenses and savings rate. A general benchmark: by 30, aim to have 1x your annual income saved. By 35, 2x. By 40, 3x. But for aggressive FIRE, you might aim for 2-3x by 30. Use our calculator with your specific numbers for an accurate timeline.
Can I still work after reaching FIRE?
Absolutely! Many FIRE retirees continue working on their own terms — part-time, consulting, passion projects, or entrepreneurship. The key difference is that you work because you want to, not because you need the money. This is often called "post-FIRE work" and can significantly reduce the risk of running out of money.

Calculate Your FIRE Timeline

Your FI Number
Savings Rate
Annual Savings
Years to FIRE
FIRE Age
Portfolio at FIRE
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