FIRE Calculator

What is the FIRE number?

Your FIRE number is the portfolio size at which your investments generate enough to cover your living expenses indefinitely. Divide your annual spending by your withdrawal rate and you have it. At a 4% withdrawal rate, that works out to 25x your annual expenses. Spend $50,000 a year? Your target is $1.25 million. Spend $80,000? You need $2 million. The simplicity is the point. One number captures your entire financial independence goal.

What is the 4% rule?

The 4% rule comes from the Trinity Study, a 1998 analysis that tested withdrawal rates against nearly a century of market data. A portfolio of stocks and bonds withdrawing 4% annually survived every 30-year retirement period in the dataset. That is a remarkably durable finding. The catch for early retirees: 30 years may not be enough. If you retire at 40, your portfolio might need to last 50 or 60 years. Most FIRE practitioners drop to a 3% to 3.5% withdrawal rate as a result, which pushes the target to 29x to 33x annual expenses instead of 25x. Slightly harder to reach, significantly harder to outlive.

Lean FIRE, Fat FIRE, Barista FIRE, and Coast FIRE

FIRE is not one thing. The community has developed several variants, each representing a different answer to "how much is enough?"

• Lean FIRE means living on under $40,000 a year, sometimes much less. The number is reachable faster, but the margin for error is thin. One major health expense or a change in what you want from life can stress the plan considerably.
• Fat FIRE targets $100,000 a year or more, keeping retirement close to what a comfortable working life looked like. The trade-off is a larger portfolio and a longer accumulation phase, often by a decade or more.
• Barista FIRE is the hybrid most people do not consider early enough. You build a partial portfolio, then cover the gap with part-time or flexible work. The smaller portfolio means you leave full-time work sooner, and the income removes the pressure of relying entirely on withdrawals during the years when sequence-of-returns risk is highest.
• Coast FIRE is arguably the most underrated milestone. It is the point where your existing portfolio, left completely alone, will compound to your full FIRE number by traditional retirement age. Once you hit Coast FIRE, you only need to earn enough to cover today's expenses. You have effectively already won the long game.

Why savings rate matters more than income

This is the insight that surprises most people when they first encounter FIRE. Someone earning $80,000 and saving 50% will reach financial independence faster than someone earning $200,000 and saving 15%. Income is only part of the story. The reason is structural: every dollar you do not spend does two things at once. It goes into your portfolio today, and it permanently lowers the portfolio size you need. Cutting $10,000 from your annual spending does not just add $10,000 to your savings each year. It also reduces your FIRE number by $250,000 at a 4% withdrawal rate. That double effect is why spending changes move your timeline by years, not months.

Fixed rate vs. historical cycles

Most FIRE calculators ask for an expected return and project a single straight line into the future. That line is useful for a rough estimate and nothing else, because markets do not deliver average returns every year. They deliver a sequence of very different years, and the order of those years matters enormously.

The historical cycles mode takes a different approach. It replays every rolling 40-year period in recorded US market history (back to roughly 1926) using your inputs, and shows the full distribution of outcomes. Some cohorts retired into 1929 or the 1966 stagflation era and ran out of money despite reasonable plans. Others caught long bull markets and ended with far more than they started with. The success rate is the share of historical cohorts whose portfolio survived the full period. At 90% or above, you are in territory most FIRE planners consider solid.

Sequence of returns risk

Sequence of returns risk sounds abstract until you work through an example, and then it is impossible to ignore. If the market drops 40% in your first two years of retirement, you are forced to sell shares at depressed prices to cover expenses. Those are shares that will never recover for you, because you already sold them. Even if the market rebounds strongly afterward, your portfolio has fewer shares participating in that recovery. A great long-run average return cannot undo the damage done by bad early years. This is why the conventional FIRE wisdom is not simply "hit your number and quit." Most practitioners build in buffers: a lower withdrawal rate, a cash or short-term bond reserve, or some part-time income in the first five to ten years. The historical cycles view captures this risk directly because periods like 1929, 1966, and 2000 are in the dataset, and they are the reason a 90% success rate is not the same as certainty.

How asset allocation affects your FIRE timeline

Stocks have historically produced better long-run returns than bonds, but with much more volatility. Bonds smooth out the ride and reduce drawdowns, at the cost of slower portfolio growth. During the accumulation phase, that trade-off usually favors a stock-heavy allocation. Most FIRE practitioners hold 80 to 100% equities while working toward their number, accepting the volatility in exchange for faster compounding. The calculus shifts at or near retirement. A large all-equity portfolio is more exposed to sequence-of-returns risk, so many people gradually shift toward a more balanced allocation as they approach and cross their FIRE number. The calculator lets you model both phases with separate return assumptions, which is worth doing if you are within a decade of your target.

How does this calculator work?

Enter your income, spending, current net worth, and expected returns split across stocks and bonds. The calculator projects your portfolio month by month until it reaches your FIRE number. In historical cycles mode, it runs that projection across every recorded 40-year market cycle and reports the range of outcomes. The sensitivity charts show how your timeline shifts as you adjust spending or returns. Most people who run them discover that spending has more leverage than return assumptions. That is worth knowing before you spend years optimizing the wrong variable.

Tips for reaching FIRE faster

• Raise your savings rate before anything else. Every dollar you do not spend reduces your FIRE number and adds to the portfolio simultaneously. No other move has that double effect.
• Max out tax-advantaged accounts (401k, IRA, HSA) early and aggressively. The tax savings compound over decades into a meaningful advantage over taxable investing.
• Use low-cost index funds. A 1% expense ratio difference sounds small and costs you years. Total market index funds from Vanguard, Fidelity, or Schwab have expense ratios near zero.
• Use Barista or Coast FIRE as intermediate targets. Getting to either one changes your relationship to work well before you reach full financial independence.
• Track your net worth consistently. Progress compounds psychologically the same way it compounds financially, and watching the number grow is one of the most reliable ways to stay the course.