🔥 FIRE Calculator

Calculate your FIRE number, savings rate, years to early retirement, and projected retirement date. Models Lean, Fat, and Barista FIRE from expenses, savings, and investment returns.

Focused on financial independence, not early retirement?

This page projects an early-retirement date with Lean/Fat/Barista variants. For FI progress tracking where work becomes optional, use the Financial Independence Calculator →

Annual Expenses ($)

Safe Withdrawal Rate (%)

Current Savings ($)

Annual Savings ($)

Expected Return (% per year)

Annual Expense Increase (% inflation)

What is FIRE?

FIRE — Financial Independence, Retire Early — is a savings strategy aimed at building a portfolio large enough to retire decades before 65. This calculator focuses on the early-retirement timeline: your FIRE number (25× annual expenses via the 4% rule), how many years until you reach it, and your projected retirement date at your current savings rate.

Use this page when the goal is retiring early and you want to model scenarios — Lean FIRE (minimal spending), Fat FIRE (comfortable lifestyle), and Barista FIRE (partial work). Time to FIRE depends mostly on savings rate, not income: saving 50% reaches FIRE far faster than saving 15%.

If your focus is the broader state of financial independence — where work becomes optional but early retirement is not the point — use the Financial Independence Calculator. For traditional retirement at normal age with corpus longevity, use the Retirement Calculator.

FIRE Formula

FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate

SWR = 4% (Trinity Study) 25× rule = 1 / 0.04 Simulation year-by-year growth

Real-World Example

$50,000/yr expenses, $200,000 saved, $24,000/yr savings, 7% return:

FIRE Number = $50,000 ÷ 0.04 = $1,250,000

Additional needed = $1,250,000 − $200,000 = $1,050,000

With 7% return + $24K/yr savings → ~18 years

How to Calculate Your FIRE Number

1Track your annual expenses — this is your baseline spending in retirement.
2Divide by your safe withdrawal rate (typically 4%) to get your FIRE number.
3Subtract current savings to find how much more you need to accumulate.
4Simulate year-by-year growth: savings grow at your expected return plus annual contributions.

How the FIRE Calculator Works

Formula, assumptions, and calculation steps for this finance tool.

Methodology

Financial calculators use time-value-of-money, rate conversion, amortization, or return formulas depending on the tool. Inputs are normalized to matching periods before the final result is calculated.

Calculation Steps

Enter the principal amounts, rates, terms, or cash flows requested by the calculator.
Convert annual rates to the correct monthly, daily, or yearly period when needed.
Apply the finance formula for payment, return, yield, or future value.
Show the result with supporting totals such as interest, gain, or balance.

Assumptions and Limits

Rates are assumed constant unless the calculator asks for a schedule.
Taxes, fees, and inflation are included only when fields are provided.
Financial results are estimates for planning, not investment or lending advice.

Frequently Asked Questions

What is FIRE?

FIRE stands for Financial Independence, Retire Early. It is a movement focused on aggressive saving and investing to accumulate enough wealth to retire decades earlier than the traditional retirement age. The core idea is building a portfolio large enough that investment returns cover your living expenses indefinitely.

What is the 4% rule?

The 4% rule (from the Trinity Study) states that you can safely withdraw 4% of your portfolio annually in retirement without running out of money over a 30-year period. This translates to needing 25× your annual expenses saved. More conservative planners use 3–3.5% SWR, especially for early retirees with longer horizons.

What is Lean FIRE vs Fat FIRE?

Lean FIRE targets minimal living expenses (under $40K/yr), requiring a smaller portfolio of around $1M. Regular FIRE is the standard 25× expenses target. Fat FIRE aims for a luxurious retirement with $100K+ annual spending, needing $2.5M or more. Barista FIRE involves retiring early but doing part-time work to cover some expenses.

How do I calculate my FIRE number?

Multiply your expected annual retirement expenses by 25 (for the 4% rule). For example, if you plan to spend $60,000 per year in retirement, your FIRE number is $60,000 × 25 = $1,500,000. Adjust this for inflation expectations and your personal risk tolerance.

Real-World Applications

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FIRE Number Calculation

Compute the exact portfolio size (25× annual expenses) you need before you can safely retire and live off investment returns.

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FIRE Date Projection

Project the calendar year you'll reach your FIRE number based on current savings rate, portfolio balance, and expected return.

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Lean FIRE vs Fat FIRE

Compare the FIRE numbers for a $30k/year Lean FIRE lifestyle versus a $80k/year Fat FIRE lifestyle to see what trade-offs are involved.

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Barista FIRE Planning

Calculate the portfolio needed to cover most expenses, with part-time work covering the remainder and providing health benefits.

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Sequence-of-Returns Stress Test

Model how a 30% market crash in year 1 of retirement affects portfolio survival over a 40-year retirement at 4% withdrawals.

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Geo-Arbitrage FIRE

Compare the FIRE number required for retiring in the US vs Portugal, Mexico, or Southeast Asia at different expense levels.

Common Mistakes

Using the 4% rule for 50-year retirements

The Trinity Study modelled 30-year retirements. For 40–50 year early retirements, a 3.5% or 3.25% SWR provides a significantly higher historical success rate.

Ignoring healthcare costs before Medicare

US early retirees must cover health insurance privately until age 65. ACA marketplace premiums can be $800–$2,000/month for a couple — often the largest FIRE expense.

Not modelling Social Security as income

Even partial Social Security benefits (delayed to 62 or 67) can dramatically reduce the required portfolio size by supplementing withdrawals in later retirement.

Lifestyle inflation underestimating the FIRE number

Many FIRE planners calculate based on current spending, then find that retirement travel, hobbies, and housing upgrades push actual expenses 20–30% higher.

Overestimating investment returns

Using 10% historical nominal returns without inflation adjustment overstates real portfolio growth. The 4% rule uses inflation-adjusted returns of ~5–7% real.

FIRE Variants Comparison

Variant	Annual Expenses	FIRE Number (25×)	Description
Lean FIRE	$25,000–$40,000	$625k–$1M	Frugal lifestyle; minimal discretionary spend
Regular FIRE	$40,000–$80,000	$1M–$2M	Middle-class comfort; no luxury
Fat FIRE	$80,000–$150,000	$2M–$3.75M	Comfortable lifestyle with travel and hobbies
Barista FIRE	Partial expenses	Smaller portfolio	Part-time work covers healthcare and gap
Coast FIRE	N/A (stop saving)	Varies by age	Let compounding carry you to FI over time

References

Cooley, Philip L., Hubbard, Carl M., and Walz, Daniel T. "Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable." AAII Journal, 1998 (Trinity Study).
Robin, Vicki and Dominguez, Joe. Your Money or Your Life. Penguin Books, 2008.
Collins, J.L. The Simple Path to Wealth. JL Collins LLC, 2016.
Adeney, Pete (Mr Money Mustache). The Shockingly Simple Math Behind Early Retirement. MrMoneyMustache.com, 2012.
Bengen, William P. "Determining Withdrawal Rates Using Historical Data." Journal of Financial Planning, 1994.