What is FIRE (Financial Independence, Retire Early)?

FIRE is a movement focused on extreme savings and investment that allows people to retire far earlier than traditional retirement age. The core idea is to accumulate enough wealth so that passive investment income covers your living expenses, freeing you from the need to work for money.

How is the FIRE number calculated?

Your FIRE number is calculated by dividing your annual expenses by your safe withdrawal rate (typically 4%). For example, if you spend $50,000 per year and use a 4% withdrawal rate, your FIRE number is $1,250,000. This is the portfolio size needed so that annual withdrawals cover your expenses indefinitely.

What is the 4% rule and is it reliable?

The 4% rule, based on the Trinity Study, suggests you can withdraw 4% of your portfolio in the first year of retirement (adjusting for inflation each subsequent year) and have a very high probability of not running out of money over a 30-year period. For early retirees with 40-50+ year horizons, a more conservative 3-3.5% rate may be prudent.

Coast FIRE means you have enough invested that, even with zero additional contributions, your portfolio will grow to your FIRE number by traditional retirement age (65). Once you reach Coast FIRE, you only need to earn enough to cover current expenses without saving anything additional.

What is the difference between Lean FIRE and Fat FIRE?

Lean FIRE targets a frugal retirement with annual spending typically under $40,000 per person, requiring a smaller portfolio (around $1M). Fat FIRE targets a more comfortable lifestyle with annual spending of $100,000 or more, requiring a larger portfolio ($2.5M+). Regular FIRE falls somewhere in between.

FIRE Calculator

Calculate your path to Financial Independence and Retire Early. Find your FIRE number, track milestones, and discover your Coast FIRE age.

FIRE Number

$1.3M

Years to FIRE

FIRE Age

Your Financial Details

Current Age

Annual Income

Annual Expenses

Current Investments

Expected Annual Return (%)

Historical stock market average: ~10%

Inflation Rate (%)

Long-term US average: ~3%

Safe Withdrawal Rate (%)

The classic 4% rule (Trinity Study)

Expected Social Security ($/month)

Many FIRE planners set this to $0

Social Security Start Age

FIRE Results

$1,250,000

Your FIRE Number

Years to FIRE29

FIRE Age59

Savings Rate37.5%

Annual Savings$30,000

Real Return3.88%

Progress to FIRE4.0%

Good Progress

A 25-50% savings rate is above average. Consider increasing it through income growth or expense reduction.

Key Insights

The 4% Rule

Based on the Trinity Study, withdrawing 4% of your portfolio in year one (adjusted for inflation each year) has historically sustained a portfolio for 30+ years. For early retirees, consider a more conservative 3-3.5% rate to account for longer retirement horizons.

Lean vs Fat FIRE

Lean FIRE means retiring on a tight budget (under $40K/year), requiring roughly $1M. Fat FIRE targets a comfortable lifestyle ($100K+/year), needing $2.5M or more. Your expenses determine which path you are on and how fast you can reach independence.

One More Year Impact

Working just one more year has a triple benefit: one more year of savings contributions, one more year of investment growth on your existing portfolio, and one fewer year of withdrawals needed. This can significantly improve your financial security.

Frequently Asked Questions

Important Disclaimer

This FIRE calculator is for educational and planning purposes only. The calculations are estimates based on the assumptions you provide and should not be considered personalized financial advice.

Investment Performance: Past performance does not guarantee future results. Market returns can vary significantly, and actual investment returns may be higher or lower than projected. The default 7% return assumption is based on historical averages.

Individual Circumstances: Your actual FIRE timeline may differ based on health, lifestyle changes, tax implications, inflation rates, sequence of returns risk, and other factors not captured in this calculator.

Professional Advice: Consider consulting with a qualified financial advisor or certified financial planner (CFP) for personalized advice that considers your complete financial picture.

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