FIRE Calculator (Financial Independence, Retire Early)

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Calculate your FIRE number, retirement date, and inflation-adjusted target, with support for 6 countries and their local currencies.

Quick answer: Your FIRE number is annual living expenses divided by your safe withdrawal rate (typically 4%, per the Trinity Study of 1998); dividing by 4% is the same as multiplying annual expenses by 25×. Spending $40,000/year means a FIRE number of $1,000,000; spending R360,000/year means R9,000,000 at the same 4% rate. Add an inflation rate below to see how many years it really takes once a rising cost of living is factored in.

yrs
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R
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R
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%
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Required. 4% = 30yr; 3.5% for 40+ yr retirement
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Optional. Grows your FIRE target each year to match a rising cost of living
Your FIRE Number
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Annual expenses ÷ Safe withdrawal rate
FIRE Number
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Years to FIRE
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FIRE Age
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Progress
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ℹ️ Based on the Trinity Study 4% rule and compound growth model.

📐 FIRE Number Formula

FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate
4% SWRFIRE Number = Annual expenses × 25
3.5% SWRFIRE Number = Annual expenses × 28.57
📝 SA Example: R30k/month, 4% SWR Annual expenses = R360,000
FIRE Number = R360,000 ÷ 0.04 = R9,000,000

How to Use the FIRE Calculator

1

Enter your annual expenses

Input your estimated annual spending in early retirement, not your current income. Your FIRE number funds spending, not a salary replacement.

2

Enter your savings and monthly contribution

Add your current portfolio balance and how much you invest each month. The gap between where those two numbers put you today and your FIRE Number is what the calculator solves for; a higher monthly contribution is the most powerful lever for cutting years off your timeline.

3

Set expected return

Enter a nominal (before-inflation) annual return; diversified equities have historically averaged around 10% nominal, or roughly 7% after inflation.

4

Add an optional inflation rate

Enter your expected annual inflation rate to see how many years it really takes to reach your FIRE Number once a rising cost of living is factored in, not just a fixed dollar target.

5

Review your FIRE number

FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate (25× expenses at the classic 4% rule). Reaching this target means your portfolio can theoretically sustain about 30 years of withdrawals.

What Is FIRE?

FIRE (Financial Independence, Retire Early) is a movement built around aggressive saving, typically 50–70% of income, to accumulate enough invested assets to live off investment returns indefinitely.

The FIRE Number

Your FIRE number is the portfolio size at which you can sustainably withdraw your annual living expenses. Based on the Trinity Study (1998), a 4% annual withdrawal from a diversified portfolio has historically been sustainable for 30 years in 95% of scenarios. Your FIRE Number = Annual Expenses ÷ 0.04 (or Annual Expenses × 25).

How to Calculate Your FIRE Number by Hand: Worked Example

The FIRE math needs only division. Say your household spends $40,000 per year. At the classic 4% safe withdrawal rate, the FIRE number is $40,000 ÷ 0.04 = $1,000,000, the familiar "25 times expenses" shortcut, because dividing by 0.04 is the same as multiplying by 25. At a more conservative 3.5% withdrawal rate, the target rises to $40,000 ÷ 0.035 = $1,142,857. Notice that trimming just $5,000 of permanent annual spending lowers the 4% target by $125,000: cutting expenses shrinks the goal by 25 times as much as it shrinks your budget.

How many years until you reach financial independence?

Starting from zero and investing $40,000 per year at a 7% return, the future value of an annuity formula shows the $1,000,000 target arrives in almost exactly 15 years: $40,000 × [(1.07¹⁵ − 1) ÷ 0.07] ≈ $40,000 × 25.13 ≈ $1,005,000. This is the engine behind the famous savings-rate table: at a 50% savings rate on an $80,000 net income, financial independence takes roughly 15 working years regardless of how large the income is, because both the target and the contributions scale together. Run the exact compounding math for your own numbers in the Compound Interest Calculator.

Which Type of FIRE Should You Aim For?

The single formula supports several strategies, each just a different expense input.

What is Lean FIRE vs Fat FIRE in dollar terms?

Lean FIRE means retiring on a deliberately frugal budget, commonly $25,000–$40,000 of annual spending, implying a portfolio of $625,000–$1,000,000 at 4%. Fat FIRE targets a comfortable lifestyle of $100,000 or more per year, requiring $2.5 million and up. The strategies differ less in math than in risk tolerance: a lean budget leaves little slack for medical costs or inflation surprises, which is why many Lean FIRE plans pair with a 3.25–3.5% withdrawal rate.

How does Coast FIRE change the calculation?

Coast FIRE asks a different question: how much must be invested today so that compounding alone hits the target by traditional retirement age, with no further contributions? A 30-year-old aiming for $1,000,000 at 65 needs $1,000,000 ÷ 1.07³⁵ ≈ $93,700 invested now. After reaching that milestone, they only need to earn enough to cover current living costs; the portfolio "coasts" the rest of the way.

Is Barista FIRE just partial retirement?

Essentially yes. In Barista FIRE, part-time work covers a slice of expenses, often chosen for employer health coverage, so the portfolio only funds the remainder. If part-time income covers $15,000 of a $40,000 budget, the portfolio must supply $25,000, dropping the required balance at 4% from $1,000,000 to $625,000. Every dollar of reliable side income permanently removes $25 from the FIRE number.

How does a market downturn right after quitting your job affect FIRE?

This is "sequence of returns risk": the same average return produces very different outcomes depending on when the bad years happen. A portfolio that drops 20% in year one of retirement, before any recovery, must sell more shares at depressed prices to fund the same withdrawal, permanently shrinking the base left to recover. Retirees close to their FIRE date commonly build a cash buffer of one to two years of expenses specifically to avoid selling into a downturn, drawing from cash while equities recover instead. Once retirees reach that date, the Retirement Calculator models how long the portfolio actually lasts as they draw it down.

⚠️ Disclaimer FIRE projections are estimates based on assumptions you control (return rate, withdrawal rate, expenses) and are not financial or legal advice; actual outcomes depend on market performance, inflation, and your personal circumstances.

Frequently Asked Questions

The 4% rule comes from the Trinity Study (1998), which found that historically, withdrawing 4% of a 50/50 stock-bond portfolio annually sustained the portfolio for 30 years in 95% of scenarios. For longer retirements (40–50 years), consider 3–3.5%.
Yes. The 4% rule is based on US market history, so investors elsewhere often adjust: countries with higher inflation or currency risk typically plan around a more conservative 3–3.5% withdrawal rate, and many international FIRE practitioners hold globally diversified index funds to reduce single-market risk. The core math, saving 25 times your annual expenses, applies anywhere.
Coast FIRE means saving enough early that compound interest will grow your portfolio to your FIRE Number by traditional retirement age, without any further contributions. You can then 'coast' and only cover current expenses. Calculator: Coast FIRE Number = FIRE Number ÷ (1+r)^(years to retirement).
FIRE stands for Financial Independence, Retire Early. The goal is to accumulate enough invested assets to live off investment returns indefinitely, typically defined as 25× annual expenses (the 4% rule). FIRE followers typically save 50–70% of income and invest aggressively in low-cost index funds.
To retire at 40 and withdraw $50,000/year: you need $1.25 million (25× expenses). Because your retirement could last 50+ years, many FIRE planners use a 3–3.5% withdrawal rate, requiring $1.43M–$1.67M. Healthcare costs before Medicare eligibility at 65 are a critical FIRE variable often underestimated.
Lean FIRE: retiring on a frugal budget (under $40K/year). Fat FIRE: retiring with a comfortable budget ($100K+/year). Barista FIRE: semi-retirement with part-time work covering expenses. Coast FIRE: having enough invested that you stop contributing but let it grow to full retirement. Each requires a different target number.
The Annual Investment Return field is a nominal (before-inflation) rate; diversified equities have historically averaged around 10% nominal, or roughly 7% after inflation. Enter your expected inflation rate in the optional Inflation Rate field and the calculator will grow your FIRE target each year to match your inflation rate, showing how many years it really takes to out-earn a rising cost of living, not just a fixed dollar figure.
Significantly. On a R360,000/year expense target with a 10% nominal return, ignoring inflation shows about 17 years to FIRE. Adding a realistic 3% inflation rate (expenses and the target both rising over time) stretches that to roughly 23 years, since the goalpost keeps moving further away each year you're still saving toward it.

Sources & Methodology

Calculations are based on the most current publicly available data from authoritative government and industry sources: