Find the smaller portfolio that funds a deliberately lean lifestyle — and how soon your savings rate gets you there.
Lean FIRE number
$933,333
3.75% of $35,000 a year.
Funding $35,000 a year at a 3.75% withdrawal rate needs a portfolio of $933,333. You have $150,000 and add $30,000 a year at 6% real returns, reaching the target in roughly 14 years. That's a lean but genuinely workable $2,917 a month.
Every dollar you cut from annual spending lowers your target by $27 — because you need roughly 27× your annual spending invested — and simultaneously frees up money to save. That's why Lean FIRE is reachable far sooner than a conventional retirement: reducing spending by $5,000 a year would cut the target by $133,333.
Retiring on a bare-bones budget means less room to absorb a health issue, a market downturn, or an unexpected major expense. A lower withdrawal rate (you're using 3.75%) helps, and so does keeping the ability to earn some income if needed. Health insurance before Medicare is often the largest and most underestimated cost in early retirement.
Lean FIRE trades a smaller portfolio for a tighter budget. See what a conventional FIRE target looks like and decide which balance you'd rather live with.
FIRE calculatorWorked scenarios with the full analysis, so you can see how the numbers move before entering your own.
A committed saver targeting a modest early-retirement budget.
Lean FIRE number
$933,333
Funding $35,000 a year at a 3.75% withdrawal rate needs a portfolio of $933,333. You have $150,000 and add $30,000 a year at 6% real returns, reaching the target in roughly 14 years. That's a lean but genuinely workable $2,917 a month.
Every dollar you cut from annual spending lowers your target by $27 — because you need roughly 27× your annual spending invested — and simultaneously frees up money to save. That's why Lean FIRE is reachable far sooner than a conventional retirement: reducing spending by $5,000 a year would cut the target by $133,333.
Retiring on a bare-bones budget means less room to absorb a health issue, a market downturn, or an unexpected major expense. A lower withdrawal rate (you're using 3.75%) helps, and so does keeping the ability to earn some income if needed. Health insurance before Medicare is often the largest and most underestimated cost in early retirement.
A minimalist target that requires a much smaller portfolio and arrives sooner.
Lean FIRE number
$666,667
Funding $25,000 a year at a 3.75% withdrawal rate needs a portfolio of $666,667. You have $120,000 and add $25,000 a year at 6% real returns, reaching the target in roughly 13 years. That's a lean but genuinely workable $2,083 a month.
Every dollar you cut from annual spending lowers your target by $27 — because you need roughly 27× your annual spending invested — and simultaneously frees up money to save. That's why Lean FIRE is reachable far sooner than a conventional retirement: reducing spending by $5,000 a year would cut the target by $133,333.
Retiring on a bare-bones budget means less room to absorb a health issue, a market downturn, or an unexpected major expense. A lower withdrawal rate (you're using 3.75%) helps, and so does keeping the ability to earn some income if needed. Health insurance before Medicare is often the largest and most underestimated cost in early retirement.
Beginning with no portfolio, showing how long a strong savings rate takes.
Lean FIRE number
$875,000
Funding $35,000 a year at a 4% withdrawal rate needs a portfolio of $875,000. You have $0 and add $35,000 a year at 6% real returns, reaching the target in roughly 16 years. That's a lean but genuinely workable $2,917 a month.
Every dollar you cut from annual spending lowers your target by $25 — because you need roughly 25× your annual spending invested — and simultaneously frees up money to save. That's why Lean FIRE is reachable far sooner than a conventional retirement: reducing spending by $5,000 a year would cut the target by $125,000.
Retiring on a bare-bones budget means less room to absorb a health issue, a market downturn, or an unexpected major expense. A lower withdrawal rate (you're using 4%) helps, and so does keeping the ability to earn some income if needed. Health insurance before Medicare is often the largest and most underestimated cost in early retirement.
A cautious withdrawal rate for a very long retirement, raising the target.
Lean FIRE number
$1,333,333
Funding $40,000 a year at a 3% withdrawal rate needs a portfolio of $1,333,333. You have $250,000 and add $40,000 a year at 6% real returns, reaching the target in roughly 14 years. That's a lean but genuinely workable $3,333 a month.
Every dollar you cut from annual spending lowers your target by $33 — because you need roughly 33× your annual spending invested — and simultaneously frees up money to save. That's why Lean FIRE is reachable far sooner than a conventional retirement: reducing spending by $5,000 a year would cut the target by $166,667.
Retiring on a bare-bones budget means less room to absorb a health issue, a market downturn, or an unexpected major expense. A lower withdrawal rate (you're using 3%) helps, and so does keeping the ability to earn some income if needed. Health insurance before Medicare is often the largest and most underestimated cost in early retirement.
Lean FIRE is early retirement funded by a deliberately modest budget — typically well below average household spending. Because the portfolio you need is a multiple of your annual spending, a leaner lifestyle means a dramatically smaller target. At a 4% withdrawal rate you need 25× your annual spending, so cutting spending by $10,000 reduces the target by $250,000.
That leverage is what makes Lean FIRE reachable years or decades earlier than a conventional retirement. It appeals to people who genuinely prefer a simpler life, or who value time and freedom over consumption. The trade-off is a tighter margin: less room for surprises, and more reliance on the budget staying lean.
A lean budget has less slack. A serious health event, a prolonged market downturn, a family need, or simply changing preferences over decades can strain a plan built with no margin. Because early retirement can span forty or more years, many people targeting Lean FIRE use a lower withdrawal rate — 3.25 to 3.5% rather than 4% — to buy extra safety.
Health insurance is the single most underestimated cost in US early retirement, since Medicare doesn't begin until 65. Marketplace premiums and out-of-pocket maximums can consume a large share of a lean budget, though subsidies based on income can help considerably. The other practical safeguard is retaining the ability to earn — even modest part-time income dramatically improves the resilience of a lean plan.
Medicare starts at 65. Marketplace premiums before then are the biggest and most-missed cost in a lean early-retirement budget.
The 4% rule was built on 30-year periods. Early retirees generally need 3.25–3.5% for comparable safety.
A plan with zero margin breaks on the first surprise. Leave room for irregular and unexpected costs.
Preferences and circumstances change over decades. A plan that requires permanent frugality is fragile.
Retaining skills and the option to earn part-time income dramatically improves a lean plan's resilience.
Lean FIRE is achieving financial independence and retiring early on a deliberately modest budget — often $25,000–40,000 a year. Because your target portfolio is a multiple of annual spending, a leaner lifestyle means a much smaller number to hit, allowing retirement years or decades earlier than conventional planning.
Divide your target annual spending by your withdrawal rate. At a 4% rate, $35,000 of spending needs $875,000; at a more conservative 3.75%, it needs about $933,000. The lower your spending and the more conservative your withdrawal rate, the more precisely you can size the number.
It carries more risk than a conventional retirement because there's less margin for shocks — health issues, market downturns, or changing preferences over a potentially 40+ year retirement. Using a lower withdrawal rate, keeping the ability to earn some income, and planning carefully for health insurance all reduce that risk substantially.
Lower than the traditional 4%, because early retirement means a longer horizon. Many people targeting Lean FIRE use 3.25–3.5%, which historically provides a better margin over 40+ year periods. The trade-off is a larger target portfolio, but it meaningfully improves the odds of the money lasting.
It's about the spending level, not the method. Regular FIRE typically targets your current or a comfortable lifestyle; Lean FIRE targets a deliberately modest one, which shrinks the portfolio needed and pulls the date forward. Fat FIRE is the opposite — a larger budget and a bigger number, reached later.
The next calculations that usually follow this one.
Your savings rate sets the date far more than your income does. This shows the year.
Find the point where your existing investments will grow into your retirement number without another dollar saved.
See how long a portfolio survives at your withdrawal rate, with inflation raising the amount you need each year.
Find your target, see the gap, and check whether you are leaving employer money behind.
Built on take-home pay, with the annual costs that break most monthly budgets.
Guides that explain the decisions behind these numbers.
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