FIRE Calculator

Your FIRE number is annual expenses divided by your safe withdrawal rate. See it and how long until you reach it.

How the FIRE Calculator works

This calculator works backward from your spending: it sets your FIRE number at your annual expenses divided by a safe withdrawal rate, then solves for how many years until your invested portfolio reaches it. Unlike a retirement tool that starts from your income or a target age, FIRE starts from the only number that matters for an early exit - what you actually spend each year.

Step 1 builds the target. FIRE number = annual expenses ÷ safe withdrawal rate (SWR). At a 4% SWR that is expenses × 25; at a 3% SWR it is expenses × 33.3. So $40,000 of spending needs $1,000,000 at 4% or $1,333,333 at 3%.

Step 2 solves for time using the future-value-of-a-series formula rearranged for the exponent:

t = ln( (FIRE × r + PMT) / (PV × r + PMT) ) ÷ ln(1 + r)

• FIRE = your target (expenses ÷ SWR)
• PV = your current invested balance
• PMT = your monthly contribution (income minus expenses)
• r = monthly return = annual real return ÷ 12
• t = months, divided by 12 for years to FI

Internally the tool: (1) converts the SWR to a multiple and computes the FIRE number; (2) converts your annual return to a monthly rate; (3) treats your savings (not your income) as PMT, because the savings rate is what drives the timeline; (4) solves for t; (5) reports years to financial independence plus the dollar gap remaining.

Edge cases it handles: a 0% real return falls back to (FIRE - PV) ÷ annual savings; if you are already at or above your FIRE number, years-to-FI is zero; and it flags an unreachable target when savings and growth can never close the gap. Because the target is expense-based, cutting spending shrinks the FIRE number and raises your contribution at the same time - a double effect no income-based tool captures.

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Example calculation

Here are three fully worked FIRE paths, each recomputed and verified. Each uses a real (inflation-adjusted) return, so the timeline is already in today's dollars.

Example 1 - Standard FIRE at 4%. You spend $40,000 a year, so your FIRE number is $40,000 × 25 = $1,000,000. You start with PV = $50,000 invested and save $30,000 a year ($2,500/month) at a 7% real return (r = 0.0058333). Solving t = ln((1,000,000 × 0.0058333 + 2,500) / (50,000 × 0.0058333 + 2,500)) ÷ ln(1.0058333) gives 188 months, or about 15.7 years. Over that span you deposit roughly $470,000; with your $50,000 head start, the remaining ~$480,000 of the million is investment growth.

Example 2 - Fat FIRE at a conservative 3%. You want $60,000 a year and use a cautious 3% SWR, so your target is $60,000 ÷ 0.03 = $2,000,000. Starting with PV = $150,000 and saving $45,000 a year ($3,750/month) at 7% real, t works out to about 17.3 years. The lower SWR buys safety but requires twice the capital of a 4% target on the same spending.

Example 3 - Lean FIRE. You trim spending to $30,000 a year at a 4% SWR, so your target is just $750,000. From PV = $20,000, saving $24,000 a year ($2,000/month) at an 8% real return, t = about 14.9 years - the smallest portfolio and the fastest finish, purely because expenses are low.

Scenario	Annual spend	SWR	FIRE number	Start (PV)	Saved/yr	Real return	Years to FI
1. Standard	$40,000	4%	$1,000,000	$50,000	$30,000	7%	15.7
2. Fat (cautious)	$60,000	3%	$2,000,000	$150,000	$45,000	7%	17.3
3. Lean	$30,000	4%	$750,000	$20,000	$24,000	8%	14.9

The lesson FIRE makes obvious: the Lean saver reaches independence first despite the smallest starting balance and contribution, because a lower spend cuts the target. To see the year-by-year balance behind any of these, run the same inputs through the investment calculator, and pressure-test the withdrawal side with the retirement withdrawal calculator.

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Tips for using the FIRE Calculator

• Cut expenses, not just earn more - it hits twice. Trimming $5,000 a year of spending lowers your 4% FIRE number by $125,000 ($5,000 x 25) AND adds $5,000 to what you can invest, so it shortens the timeline far more than a $5,000 raise that you spend.
• Track your savings RATE, not your income. At a 5% real return from zero, a 50% savings rate reaches FI in about 17 years while a 20% rate takes about 37 years - the same income at a different rate more than doubles the wait.
• Use a 3% to 3.5% SWR if you retire before 50. The classic 4% rule was modeled on a 30-year retirement; a 45-year-old planning for 45+ years should use 28x to 33x expenses, not 25x, to survive sequence-of-returns risk.
• Keep 2 to 3 years of spending in cash or short bonds at the start. Drawing from this bucket during an early bear market avoids selling stocks at the bottom - the single biggest defense against sequence risk in the first decade of early retirement.
• Solve the pre-59.5 access problem before you quit, not after. Money in a 401(k) or traditional IRA faces a 10% early-withdrawal penalty, so set up a Roth conversion ladder (convert, wait 5 years, withdraw the converted amount penalty-free) or a SEPP / 72(t) series first.
• Budget the healthcare gap explicitly. Medicare starts at 65, so an early retiree must self-fund ACA marketplace coverage for years - and because ACA subsidies are based on taxable income, a low-withdrawal FIRE plan can actually qualify you for large premium subsidies.
• Build a taxable brokerage bridge. Because retirement accounts are penalized before 59.5, hold enough in a regular taxable account to cover the years between early retirement and penalty-free access, then let the sheltered accounts keep compounding untouched.
• Coast FIRE can free you years before full FIRE. Once your invested balance is large enough to grow into your FIRE number by 65 with zero new contributions, you only need to earn enough to cover current expenses - you can stop saving entirely.
• Model in REAL returns (about 4% to 7%), not nominal 10%. A FIRE number is a purchasing-power goal decades out, so subtract inflation from your return or your years-to-FI will be too optimistic and your withdrawals will overstate real spending.
• Stress-test your SWR against a bad first decade. A portfolio that averages 7% but loses 30% in years one and two can fail even at a 4% rate; modeling a downside-first sequence is more honest than trusting the long-run average.

FIRE calculator vs a retirement calculator: what is actually different

A FIRE calculator targets a portfolio sized to your expenses and solves for how few years it takes; a standard retirement calculator targets a fixed age (usually 65-67) and checks whether your income-based savings will last. The math overlaps, but the framing - and the answers - diverge sharply.

Dimension	FIRE calculator	Retirement calculator
Goal is set by	Annual expenses ÷ SWR (25x-33x spending)	A target retirement age
Key lever	Savings RATE (income minus spending)	Contribution amount and years to 65
Withdrawal horizon	40-50+ years (early exit)	~25-30 years
Big risk it must model	Sequence-of-returns risk + pre-59.5 access	Outliving savings; Social Security timing
Typical SWR assumed	3% to 4%	4%+, often with Social Security offset

The practical difference: FIRE rewards cutting expenses because lower spending shrinks the target and raises your savings simultaneously, while a conventional plan mostly rewards saving more dollars. If your real goal is a normal-age exit with Social Security factored in, use the retirement calculator; if you want to escape decades early, this expense-first model is the right frame. Either way, validate the spend-down with the retirement withdrawal calculator.

Why your savings rate - not your income - decides when you retire

Your savings rate is the single strongest driver of years-to-FI, because it sets both how fast you accumulate and how small your target needs to be. Someone earning $300,000 who spends $250,000 will retire later than someone earning $80,000 who spends $40,000 - the high earner has a bigger target and a smaller cushion. The table below assumes you start from $0 and earn a 5% real return; it shows the brutal math of the rate alone.

Savings rate	Spend you must cover	Years to FI (5% real, from $0)
10%	90% of income	~51 years
20%	80%	~37 years
30%	70%	~28 years
40%	60%	~22 years
50%	50%	~17 years
60%	40%	~12 years
70%	30%	~9 years

Notice the savings rate appears on both sides of the equation: a higher rate means more money invested each year AND a lower FIRE number, because you live on less. This is why FIRE communities obsess over the rate rather than the paycheck. To find room to raise yours, start with your real take-home using the take-home pay calculator, then route every raise straight into investing with the pay raise calculator instead of inflating your lifestyle.

Lean, Fat, Coast, and Barista FIRE: the four variants

The FIRE label splits into four flavors that change either the size of the target or how you fund the gap. All use the same expenses ÷ SWR engine; they differ in the spending assumption and whether you keep working.

• Lean FIRE - a low-expense version, often under $40,000 a year for a household, producing a small target (around $750,000-$1,000,000 at 4%). Fastest to reach, least margin for error.
• Fat FIRE - a comfortable or luxury spend ($100,000+ a year), needing $2,500,000 or more. Slower, but with real buffer.
• Coast FIRE - you have invested enough that it will grow into your full FIRE number by traditional retirement age with no new contributions; from there you only need to cover current expenses. At a 5% real return, roughly $227,000 invested at age 30 coasts to about $1,250,000 by 65.
• Barista FIRE - part-time or gig work covers part of your spending (and often health insurance), so your portfolio only funds the rest. If a part-time job covers $20,000 of a $50,000 budget, you self-fund $30,000, dropping the target from $1,250,000 to $750,000 at a 4% SWR.

Coast and Barista are powerful because they decouple "stop saving" from "stop working" - milestones you can hit years before full independence. Map the lump-sum growth behind a Coast number with the compound interest calculator, and size the broader picture with the net worth calculator.

Sequence-of-returns risk and the pre-59.5 access problem

The two dangers unique to retiring early are sequence-of-returns risk - a market crash in your first few retirement years - and the 10% penalty on tapping retirement accounts before age 59.5.

Sequence risk: two retirees with the same average return can end up wildly differently if one hits losses early. Withdrawing a fixed amount while the portfolio is down forces you to sell more shares at low prices, permanently shrinking the base that has to recover. A 40-year horizon magnifies this versus a normal 25-year retirement, which is why early retirees lean toward a 3-3.5% SWR and keep a 2-3 year cash/bond buffer to avoid selling stocks in a downturn.

Early-access problem: 401(k) and traditional IRA withdrawals before 59.5 generally trigger a 10% penalty plus income tax. Two standard workarounds:

• Roth conversion ladder - convert traditional funds to Roth, wait the 5-year seasoning period, then withdraw the converted principal penalty-free. Start the ladder about 5 years before you need the cash.
• SEPP / Rule 72(t) - take Substantially Equal Periodic Payments based on IRS life-expectancy tables; done correctly this avoids the penalty but locks you into the schedule for 5 years or until 59.5, whichever is longer.

A taxable brokerage bridge - enough ordinary investments to cover the years until 59.5 - lets the sheltered accounts keep compounding untouched. Plan the drawdown order with the retirement withdrawal calculator.

The healthcare gap before Medicare

Medicare does not start until 65, so anyone retiring earlier must self-fund health insurance for the entire gap - a cost FIRE plans routinely underestimate. For a retirement at 50, that is 15 years of coverage to budget. In the US the main option is the ACA marketplace, where premiums vary by age, location, and plan tier.

There is a counterintuitive upside built into FIRE: ACA premium subsidies are based on your taxable income, not your net worth. A FIRE household living off Roth withdrawals, long-term capital gains harvested at low rates, and cash can show a modest taxable income while owning a large portfolio - which can qualify it for substantial premium tax credits. This makes managing reported income a core FIRE skill: keep taxable withdrawals in a band that preserves subsidies without triggering penalties.

Practical steps: add a realistic annual health-insurance line to your expenses before computing your FIRE number (so it sits inside the 25x-33x multiple), keep a separate cash reserve for deductibles and out-of-pocket maximums, and revisit the estimate yearly since premiums move. Because this cost sits inside annual expenses, every $1,000 of premium adds about $25,000 to your 4% FIRE target - another reason early retirees model healthcare explicitly rather than hoping it nets out.

Common mistakes that wreck a FIRE plan

The most common FIRE mistake is sizing the target off your current take-home pay instead of your actual annual expenses. The whole model is expense-driven; get the spending number wrong and everything downstream is wrong. Watch for these:

• Building the target on income, not spending. FIRE number = expenses ÷ SWR. Using income inflates the target and hides how much cutting costs would help.
• Using nominal returns for a real goal. Plugging in 10% nominal makes the timeline look short, but your future spending rises with inflation too. Model in real returns (about 4-7%) so the target and the withdrawals are in the same dollars.
• Trusting the 4% rule for a 50-year retirement. It was calibrated to ~30 years. Early retirees should drop to 3-3.5% (28x-33x expenses) to survive a longer horizon.
• Ignoring sequence-of-returns risk. A plan that works on the average return can still fail if losses hit in the first few years. Keep a cash buffer and stay flexible on withdrawals.
• Forgetting the 59.5 wall. Counting 401(k)/IRA money you cannot touch penalty-free yet, with no Roth ladder, SEPP, or taxable bridge in place.
• Omitting healthcare. Leaving ACA premiums out of expenses understates the FIRE number by tens of thousands of dollars of required capital.
• Confusing it with a round-number goal. Chasing a flat $1,000,000 regardless of spending. If you live on $60,000, $1M is only 16.7x - not financial independence. Use the millionaire calculator for a fixed-dollar target instead.

How to compute your FIRE number and timeline in Excel or Google Sheets

You can reproduce this entire page with two spreadsheet steps: one cell for the FIRE number and one NPER formula for the years.

Step 1 - the target. If A1 holds annual expenses and A2 holds your SWR as a decimal (0.04 for 4%):

=A1/A2

For $40,000 of spending at 4%, that returns 1,000,000. Use 0.03 for the cautious 33x version.

Step 2 - years to FI. NPER returns the number of periods to reach a future value. Using annual figures:

=NPER(rate, pmt, pv, fv)

For a $30,000-a-year saver starting from $0 at a 7% real return, targeting $1,250,000:

=NPER(0.07, -30000, 0, 1250000)

That returns about 20.2 years. The payment and present value are negative because they are cash leaving your pocket while the target is positive. If you prefer monthly precision, use a monthly rate (annual ÷ 12) with monthly contributions - for Example 1 above, =NPER(0.07/12, -2500, -50000, 1000000) returns about 188 months, or 15.7 years, matching the calculator.

By hand, use t = ln((FIRE × r + PMT) / (PV × r + PMT)) ÷ ln(1 + r). A #NUM! error means your savings and return can never reach the target - lower the goal or raise the contribution. For the dollar path behind the formula, the future value calculator shows where the balance lands at any year.

FIRE number and 4% withdrawal quick reference

Your FIRE number is your annual spending times 25 at a 4% safe withdrawal rate (about 33x, or 1 ÷ 0.03, at a 3% rate), and that same portfolio then pays back roughly 4% per year. The table below recomputes the target both ways for common spending levels, plus the safer 3% draw the 25x portfolio could sustain. All withdrawal figures are pre-tax, so budget separately for taxes and the pre-Medicare healthcare gap.

Annual spending	25x target (4% SWR)	33.3x target (3% SWR)	Income at 4% of 25x	Safer 3% draw on the 25x
$40,000	$1,000,000	$1,333,333	$40,000	$30,000
$50,000	$1,250,000	$1,666,667	$50,000	$37,500
$60,000	$1,500,000	$2,000,000	$60,000	$45,000
$80,000	$2,000,000	$2,666,667	$80,000	$60,000
$100,000	$2,500,000	$3,333,333	$100,000	$75,000

The last column shows the margin you build by stockpiling a 4% target but only drawing 3%: a $1,000,000 portfolio meant for $40,000 of spending throws off $40,000 at 4% but a more durable $30,000 at 3%. Savings rate, not income, sets how long it takes to get there. Approximate years to FIRE starting from $0:

Savings rate	Years to FIRE (5% real)	Years to FIRE (7% real)
20%	~37	~31
30%	~28	~24
40%	~22	~19
50%	~17	~15
60%	~12	~11
70%	~9	~8

Sanity-check the accumulation side against a round target with the millionaire calculator and the full snapshot with the net worth calculator.

Related on this site

Retirement Calculator · Retirement Withdrawal Calculator · Investment Calculator · Compound Interest Calculator · Millionaire Calculator · Net Worth Calculator

For a related deep dive, see SEC Investor.gov on the 4% withdrawal concept.

FIRE Calculator — frequently asked questions

Why 4%?

The 4% rule suggests a portfolio can sustain ~4% annual withdrawals; some use 3–3.5% to be safer.

Does it ignore taxes?

Yes — real plans must budget for taxes and healthcare, which can raise the target.

What is the 4% rule?

A guideline that a portfolio can sustain ~4% annual withdrawals for ~30 years.

Is FIRE realistic?

It requires a high savings rate and disciplined investing, but the math is sound.

What is my FIRE number if I spend $60,000 a year?

Your FIRE number is $1,500,000 at a 4% safe withdrawal rate. The standard rule multiplies annual spending by 25 (1 / 0.04), so $60,000 x 25 = $1,500,000. If you want a safer 3% rate, use about 33x (1 / 0.03) for a $2,000,000 target; at 3.5% it is about 28.6x, or roughly $1,714,000. Base the figure on your real post-retirement <em>expenses</em>, not income. Estimate yours with the FIRE Calculator on this page.

How much does a $1.25 million portfolio let me withdraw each year?

A $1.25 million portfolio supports about $50,000 per year at a 4% withdrawal rate, or roughly $4,167 per month. At a more conservative 3% the figure drops to $37,500 ($3,125/month). These are pre-tax figures, so set aside something for taxes and the pre-Medicare healthcare gap. The 4% guideline targets a roughly 30-year horizon; very early retirees often prefer 3% to 3.5%. Model withdrawals with the <a href="/retirement-withdrawal-calculator/">Retirement Withdrawal Calculator</a>.

How many years to FIRE if I save 50% of my take-home pay?

Saving 50% of take-home pay puts you about 17 years from FIRE at a 5% real return (about 15 years at 7%), starting from zero. Savings rate, not income, drives the timeline: a 50% rate means you live on half and bank half, so each working year roughly buys one retired year. For comparison, a 20% rate takes about 37 years and a 70% rate about 9 years. The income level barely matters - the rate is what moves the number.

Why does raising my savings rate from 20% to 30% cut so many years?

Jumping from a 20% to a 30% savings rate cuts your time to FIRE by roughly 9 years (about 37 down to 28 at a 5% real return from zero). It works both ways at once: spending less shrinks your 25x target <em>and</em> the extra cash speeds accumulation. Because the savings rate sits in both the numerator and denominator of the math, each percentage point is far more powerful than a raise of the same dollar amount that you then spend.

What is my Coast FIRE number at age 35 for $50,000 of spending?

At age 35 your Coast FIRE number is about $289,000, assuming a 5% real return to age 65 and a $1.25 million target (25 x $50,000). Coast FIRE means you have invested enough that compounding alone reaches your goal with <em>no further contributions</em>: $289,000 x 1.05³⁰ is about $1.25 million. At a 7% real return the coast number falls to roughly $164,000. After that you only need to earn enough to cover current expenses.

How much do I need for Barista FIRE if part-time work earns $20,000?

If part-time work covers $20,000 of $50,000 in annual expenses, your Barista FIRE portfolio target is $750,000. The portfolio only has to fund the $30,000 gap, so $30,000 x 25 = $750,000 at a 4% rate. A bonus reason people choose Barista FIRE is that an employer often provides health insurance, closing the costly pre-Medicare coverage gap. Test different gaps with the FIRE Calculator above.

What is the difference between Lean FIRE and Fat FIRE in dollars?

Lean FIRE funds a bare-bones budget while Fat FIRE funds a comfortable one, and the gap is huge. A Lean FIRE budget of $30,000 a year needs about $750,000 (25x); a Fat FIRE budget of $120,000 needs about $3,000,000. The 25x math is identical - only the expense input changes. That is why FIRE planning starts with an honest spending estimate, since every $1,000 of yearly spending adds $25,000 to your target.

How much does cutting $5,000 a year of spending lower my FIRE number?

Cutting $5,000 of annual spending lowers your FIRE target by $125,000. The 25x rule means each dollar of recurring expense costs $25 of portfolio, so $5,000 x 25 = $125,000 less to save. It also frees $5,000 to invest each year, so a permanent spending cut helps twice at once. This double effect is why trimming fixed costs like housing beats one-time frugality for reaching financial independence faster.

How do I calculate years to FIRE by hand?

Solve the savings-annuity formula for the number of years: n = ln(1 + T x (1 - s) x r / s) / ln(1 + r), where T is your target as a multiple of spending (25 at 4%), s is your savings rate as a fraction of take-home pay, and r is your real return. Example: at a 40% rate and 5% real return, T x (1 - s) x r / s = 25 x 0.6 x 0.05 / 0.4 = 1.875, so n = ln(2.875) / ln(1.05) is about 21.6 years.

How do I model years to FIRE in Excel?

Use NPER in one cell: =NPER(rate, -annual_savings, -current_balance, fire_number). For a 7% real return, $30,000 saved per year, $0 start, and a $1,250,000 target, =NPER(0.07,-30000,0,1250000) returns about 20.2 years. Enter savings and balance as negatives (cash out) and the target as positive. Change the rate to 0.05 to stress-test a lower real return, since the return assumption moves the answer more than almost anything else.

Is the 4% rule safe for a 45-year early retirement?

The 4% rule is less safe over 45 years because it was built around roughly 30-year retirements. A longer horizon raises the odds that a bad early stretch drains the portfolio, so many early retirees use 3% to 3.5% instead. At 3% you need about 33x expenses ($2,000,000 for $60,000 of spending) rather than 25x ($1,500,000) - a meaningful difference. Flexibility, like trimming withdrawals in down years, improves survival more than chasing one perfect rate.

What is sequence-of-returns risk in early retirement?

Sequence-of-returns risk is the danger that poor returns early in retirement, while you are also withdrawing, permanently shrink your portfolio. Example: a $1,000,000 portfolio you draw $40,000 from (leaving $960,000) that then falls 30% drops to $672,000; the same $960,000 followed by a 20% gain leaves $1,152,000 - a $480,000 swing from timing alone. Holding 1 to 3 years of cash and cutting withdrawals after a crash are the main defenses early retirees use.

How do I access retirement money before age 59.5 without penalty?

Two main paths avoid the 10% early-withdrawal penalty: a Roth conversion ladder and SEPP/72(t) payments. A Roth ladder moves money from a traditional account to a Roth each year, then withdraws each converted amount penalty-free after a 5-year wait - so you start converting about five years before you need it. SEPP/72(t) locks you into fixed annual withdrawals for at least 5 years or until 59.5, whichever is longer. Roth contributions themselves are always withdrawable.

How much can a 72(t)/SEPP plan pay from a $500,000 IRA?

A $500,000 IRA under the 72(t) amortization method pays roughly $30,000 per year for someone around age 50, using a 5% rate and a single-life expectancy near 34 years. The exact figure depends on the IRS-approved interest rate and the method (RMD, amortization, or annuitization). The catch: once started, you must keep the payments unchanged for at least 5 years or until age 59.5, whichever is longer, or face retroactive penalties. Many FIRE retirees fund SEPP from a separate, smaller IRA.

How much should I budget for healthcare before Medicare?

Budget thousands of dollars per year for the pre-Medicare gap, because Medicare does not start until age 65. If you retire at 50, that is 15 years of self-funded coverage, usually an ACA marketplace plan. Premium tax credits are tied to your taxable income, so early retirees who live partly off cash or Roth principal can keep reported income low and shrink premiums. Because this cost is recurring, add it to expenses first: $6,000 a year of premiums raises your 25x target by $150,000.

Is Coast FIRE worth it compared to full FIRE?

Coast FIRE is worth it if you want to stop saving and ease off sooner without quitting work entirely. Once you hit your coast number - for example about $231,000 at age 35 for $40,000 of spending at a 5% real return - compounding alone reaches your full target by 65, so you only need to earn enough to cover today's bills. The tradeoff is you keep working longer than with full FIRE, but with far less savings pressure and more flexibility.

Guides & articles

• What Is My FIRE Number, and How Do You Calculate It?
• Coast FIRE: How Much You Need So You Can Stop Saving

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