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Free · No sign-up · Updated November 11, 2026

Lean FIRE Calculator

Lean FIRE is financial independence on a frugal budget, roughly under $40,000 a year, so you need a smaller portfolio and can retire sooner. Build your lean budget line by line, compare it with what typical retirees spend, and see your Lean FIRE number and how many years it takes to reach it.

Your numbers

Lean budget (per month)
$/mo
$/mo
$/mo
$/mo
$/mo
$/mo
$/mo
$/mo
Total$2,750/mo · $33,000/yr

Safety buffer on top of the budget

A lean budget has little room for surprises. A buffer covers repairs, medical bills and price rises you didn't plan for.

Getting there
yrs old
$

401(k), IRA, HSA and taxable brokerage. Not your home or emergency fund.

$

After tax. Add your partner's if you plan together.

$

Savings rate: 46% of take-home pay.

Assumptions

Real return used: 3.79% a year after inflation and fees. All results are in today's money.

%

Nominal, before inflation. The S&P 500 returned 10.0% a year from 1928-2025; Vanguard's 10-year forecast for US stocks is 4.8%-6.8%.

%

US inflation averaged about 3.0% a year from 1928-2025, and 3.7% in the 12 months to September 2026.

%

Fund expense ratios plus any advisory fee. Broad index funds often cost 0.03%-0.20%.

%

4% is the classic rule. A lean budget has little slack to cut in a bad market, so 3.5% or a buffer adds safety.

yrs old

Planning to 95 or later protects against outliving your money.

%

Used by the risk tests. The rest is assumed to be 10-year US Treasuries, rebalanced yearly.

Risk test returns

Replays actual 1928-2025 returns (minus fees), like the Trinity study and FIRECalc. Past returns were higher than most forecasts.

Your Lean FIRE number

$825,000

That funds $33,000 a year at a 4% withdrawal rate. Saving $30,000 a year (46% of take-home pay), you'd reach it at age 45, in about 14.5 years.
Progress: $150,000 of $825,00018%

Lean budget

$2,750/mo

$33,000 a year

Lean FI age

Age 45

15 years away

Safer target at 3.5%

$942,857

About 1.9 years more saving

vs 65+ households

51%

Average spend: $64,445 (BLS)

Where your lean budget goes

$33,000 a year ($2,750 a month) in today's dollars, largest line first.

How lean is your budget?

Yearly spending, compared with average US households in the 2025 Consumer Expenditure Survey (BLS).

  • Your lean budget$33,000
  • Average household, age 65+$64,445
  • Average household, all ages$81,905
Savings rate vs years to financial independence

Years to reach your $825,000 Lean FIRE number from $150,000 today, at each share of your $65,000 take-home pay.

  • Years until FI
  • You

Does a lean plan have enough margin?

Markets don't deliver an average return every year. A crash right after you retire can sink a plan that looks fine on average. These two tests use 98 years of US stock, bond and inflation data.

Monte Carlo success rate

85%

2,000 simulated lifetimes to age 95

Historical success rate

84%

49 start years tested. Worst: retiring in 1966 ran out after 28 years.

Range of outcomes (Monte Carlo)

2,000 simulations, each year drawn from a random year of US market history (1928-2025). Today's money.

  • Middle 80% of outcomes
  • Middle 50%
  • Median
The luckiest 10% of outcomes extend above the top of the chart. Switch to Table to see every value.
Every 50-year retirement since 1928

Each bar is a retirement that started in that year and replayed actual US returns and inflation. Today's money.

  • Money left at the end
  • Ran out of money

How this is calculated

Lean FIRE number = lean budget ÷ withdrawal rate = $33,000 ÷ 4% = $825,000. Years to Lean FI grow $150,000 at a 3.79% real return, adding $30,000 at the end of each year, until the balance reaches that number. Social Security is left out, which adds a margin later in life.

How to use this Lean FIRE calculator

  1. Fill in each line of your lean budget per month: housing, food, transportation, healthcare and the rest. The total updates as you go.
  2. Enter your age, what you have invested, your take-home pay and how much you save each year.
  3. Pick a safety buffer and check the withdrawal rate under Assumptions. Lean plans benefit from both.

Results update as you type. Copy the share link to save your budget, or download it with the year-by-year projection as a CSV.

What is a Lean FIRE number?

Your Lean FIRE number is the portfolio that pays for a frugal budget for the rest of your life. Most lean budgets land between $25,000 and $40,000 a year, so most Lean FIRE numbers fall between $625,000 and $1,230,769, depending on the budget and how cautious a withdrawal rate you choose:

Lean FIRE number by yearly budget (our calculation, today's dollars)
Yearly budgetAt 4%At 3.5%At 3.25%
$25,000 ($2,083/mo)$625,000$714,286$769,231
$30,000 ($2,500/mo)$750,000$857,143$923,077
$35,000 ($2,917/mo)$875,000$1,000,000$1,076,923
$40,000 ($3,333/mo)$1,000,000$1,142,857$1,230,769

The 4% column suits a traditional 30-year retirement. Lean FIRE often starts in your 30s or 40s, and for 50-60 year retirements research points to 3.25%-3.5%[4], which is why the lower columns exist.

How is the Lean FIRE number calculated?

The calculator finds the portfolio that can fund your lean budget for your whole retirement at your withdrawal rate:

Lean FIRE number = yearly lean budget × (1 + buffer) ÷ withdrawal rate

At a 4% withdrawal rate that is 25 times your budget, the rule based on William Bengen's 1994 research[3]. Years to Lean FI then come from growing what you have today, plus what you save each year, at your expected real return until you reach the number.

Worked example

Jamie, 30, has $150,000 invested and saves $30,000 a year. Their lean budget is $1,000 a month for housing, $500 for food, $400 for healthcare and $850 for everything else: $33,000 a year. The real return is 3.79%.

  • Lean FIRE number: $33,000 ÷ 4% = $825,000
  • Years to Lean FI: about 14.5 years, so Jamie could retire around age 45
  • At a safer 3.5%: $942,857, about 16.4 years

What assumptions does the calculator use?

Everything is in today's dollars. The real return comes from the Fisher equation, (1 + return − fees) ÷ (1 + inflation) − 1.

  • Return: 7% default with 3% inflation. The S&P 500 returned 10.0% a year from 1928 to 2025[6], but Vanguard's 10-year forecast for US stocks is 4.8%-6.8%[7].
  • Withdrawal rate: 4% default. You can lower it under Assumptions; the result also shows a safer target alongside.
  • Budget defaults: $2,750 a month. A single person or frugal couple in a lower-cost area. Replace every line with your own numbers.

What does a Lean FIRE budget look like next to average spending?

Lean is far below average. All US households spent $81,905 on average in 2025[2], and households headed by someone 65 or older spent $64,445[13]. Our default lean budget of $33,000 is 51% of the 65+ average. Here it is line by line, against the closest Bureau of Labor Statistics category from the same table:

Lean default budget vs BLS 2025 average spending, per year
Budget line (BLS category)Lean default65+ householdsAll households
Housing (Shelter)$12,000$13,992$17,626
Food$6,000$8,226$10,633
Transportation$3,000$10,109$13,492
Healthcare$4,800$7,986$6,470
Utilities & phone (Utilities, fuels and public services)$2,400$4,680$4,931
Travel & fun (Entertainment)$2,400$2,975$4,084

Three things stand out. Transportation is where lean budgets differ most: the default is 30% of the 65+ average, which in practice means one older car or none. Food is closer, at 73%, because groceries are hard to cut much further. Healthcare runs the other way for early retirees: the 65+ average reflects people on Medicare, while someone retiring at 40 pays Marketplace premiums for 25 years first, so don't copy that line from older households.

Two caveats keep the comparison honest. These are averages for households of 1.7 people (65+), not a target for your household size. And the BLS totals include "personal insurance and pensions", which covers Social Security and pension contributions that a retiree no longer pays, but exclude personal income taxes[14]. If your withdrawals will be taxed, add that tax to your budget. Funding the 65+ average at 4% would take $1,611,125, while the lean budget needs $825,000: a difference of $786,125 you don't have to save.

Costs lean budgets often miss

  • Replacing things. Cars, roofs, appliances and laptops don't show up in a typical month. Divide each one's cost by how many years it lasts and add that to the budget.
  • Out-of-pocket healthcare. Deductibles, dental work and glasses on top of premiums.
  • Taxes. Small for most lean budgets, but not always zero, especially with traditional 401(k) or IRA withdrawals.
  • Life changes. A partner, children, pets, or helping parents can each add thousands a year. If any is likely, price it in now or keep a buffer.

Does geographic arbitrage work for Lean FIRE?

It can, within limits. The Bureau of Economic Analysis measures how price levels differ between states. In 2024 they ranged from 110.7% of the national level in California, the most expensive state, to 86.9% in Arkansas, the cheapest[15]. Applied to our default budget, the same basket of goods and housing would cost about $36,531 a year at California's average price level and $28,677 at Arkansas's. At 4%, that is the difference between a $913,275 and a $716,925 Lean FIRE number.

Treat that as an upper bound on the benefit. State averages hide big gaps between cities and rural areas, and housing varies far more than groceries. Moving has real costs, health insurance premiums and provider networks differ by area, and being far from family can bring travel costs back in. Price a specific place, ideally by living there for a few months, before you plan around it.

What is the downside of Lean FIRE?

Little margin for shocks. Higher-spending retirees can follow guardrail rules, cutting spending 10% when their withdrawal rate drifts 20% above where it started[10]. On a lean budget most spending is essential, so there's less to cut. Time is the other risk: a 4% rule with a 50/50 portfolio had about 95% success over 30 years but only about 65% over 60 years[5].

Overspending hurts more than it looks. If Jamie retires on exactly $825,000 but actually spends 10% more than planned, the withdrawal rate is 4.4%, not 4%. In our replay of every 50-year retirement in the 1928-2025 market data[6], with an 80/20 stock and bond portfolio, 4% lasted in 80% of start years and 4.4% in only 67%.

Two simple fixes: a lower withdrawal rate or a buffer. A 10% buffer on Jamie's budget raises the number to $907,500; a 3.5% rate raises it to $942,857. A cash reserve of a year or two of spending also lets you avoid selling after a crash, which matters because returns early in retirement do the most damage[9].

How does Lean FIRE handle health insurance?

Often well, if you manage your income. Marketplace premium tax credits are available in all states for incomes between 100% and 400% of the federal poverty level; the 2026 guidelines are $15,960 for one person and $21,640 for two, so the range runs from $15,960 to $63,840 for a single person. Below 138% you may qualify for Medicaid instead if your state expanded it, and below 100% you probably won't qualify for Marketplace savings[16].

Marketplace income is not the same as spending. It counts most traditional IRA and 401(k) withdrawals and capital gains, but not qualified distributions from a Roth account[17], so the mix of accounts you draw from decides where you land. Enhanced subsidies expired at the end of 2025[11] and, for 2027 coverage, income above 400% still gets no premium tax credit[18]. That cliff rarely bites a lean household, but a large one-off gain can. Price a real plan before you trust the healthcare line.

Can a little part-time income make Lean FIRE safer?

Yes, and it takes surprisingly little. Retiring at 40 on our default budget needs $825,000 at 4% with the money lasting to 95. Earning just $10,000 a year for the first five years lowers that to $778,291; for the first ten years, to $739,010 (our calculation, with the same year-by-year engine as the Barista FIRE calculator).

The bigger benefit is flexibility. Part-time income is the one lever a lean retiree can pull after a crash, when cutting spending further is not realistic. Even a plan you fund in full benefits from knowing you could earn a few thousand dollars if you had to.

How much does your savings rate matter?

More than anything else. With 5% real returns and a 4% withdrawal rate, saving 10% of your pay means about 51 working years, while saving 50% means about 16[8]. Lean FIRE works so fast because a small budget raises your savings rate and lowers your target at the same time.

Starting from zero on $65,000 of take-home pay with our default lean budget, saving 30% would take about 26 years and saving 50% about 18 years (our calculation). The savings-rate chart in the calculator shows this curve for your own numbers, and the savings rate calculator goes deeper. For more on the math, see how to calculate your FIRE number.

Lean FIRE vs other types of FIRE

TypeAnnual spendingWhat it means
Lean FIREUnder about $40,000Very frugal budget, often in a low-cost area
FIREAbout $40,000-$80,000Portfolio covers a typical lifestyle
Chubby FIREAbout $80,000-$120,000Comfortable, some luxuries
Fat FIRE$120,000+No meaningful budget constraints
Coast FIREAnySaved enough to stop investing; work covers current bills
Barista FIREAnyPart-time income covers part of spending

Spending bands are this site's rough conventions, not official definitions; they shift with inflation and cost of living.

Frequently asked questions

What counts as lean FIRE?

There's no official line. Lean FIRE means retiring on a minimalist budget that covers the essentials with little room for extras[1]. As a rough guide, this site uses under about $40,000 a year for a household, a community convention rather than a rule. What matters more than the label is that your budget covers the essentials, including health insurance, with some room left for surprises.

Can you lean FIRE on $1 million?

Yes. $1,000,000 supports about $40,000 a year at a 4% withdrawal rate and $35,000 at 3.5%. That covers our default lean budget of $33,000 with room to spare, which is exactly the margin a lean plan needs. If you retire very young, the lower rate is the safer guide.

Is $500K enough for lean FIRE?

Not on its own for most lean budgets: $500,000 supports $20,000 a year at 4%. With part-time work it can be. Retiring at 40 on our default budget of $33,000, you would need about $27,306 a year of after-tax part-time income until 55, or $19,099 until 65, to make $500,000 last to 95 (our calculation, 4% withdrawal rate, no Social Security).

What's the difference between lean FIRE and barista FIRE?

Lean FIRE means your portfolio covers all of a small budget and you stop working. Barista FIRE means your portfolio covers part of a normal budget and part-time work covers the rest for a while. Some people combine them: a lean budget plus a little part-time income is one of the most resilient plans. Try the Barista FIRE calculator to compare.

What are the risks of lean FIRE?

The main risk is having nothing to cut. A big medical bill, a car replacement or a few years of high inflation hit harder when every dollar is already spoken for. A market crash early in retirement does the most damage[9]. The fixes are a buffer in the budget, a lower withdrawal rate, a cash reserve, or the willingness to earn a little income if markets fall.

Should a Lean FIRE plan count on Social Security?

This calculator leaves it out, which builds in a margin for later life. Full retirement age is 67 for anyone born in 1960 or later[12]. If you retire very early your benefit may be smaller, because fewer working years count toward it. The FIRE number calculator lets you add it.

Sources

Figures checked against each source on November 11, 2026.

  1. [1]What is the FIRE movement? · CNBC Select, September 24, 2024.The FIRE target of 25x annual expenses and definitions of Lean, Fat, Barista and Coast FIRE.
  2. [2]Consumer Expenditures, 2025 · U.S. Bureau of Labor Statistics, October 29, 2026.Average annual spending by all US households in 2025: $81,905. Average annual expenditures in 2025 by income quintile: lowest $37,935, second $51,405, third $68,983, fourth $92,250, highest $159,512 (Table 3). Average income before taxes for all consumer units was $110,847.
  3. [3]Determining Withdrawal Rates Using Historical Data · William P. Bengen, Journal of Financial Planning, October 1994.Origin of the 4% rule: a 4% inflation-adjusted first-year withdrawal lasted at least 33 years in every historical period tested. Used Ibbotson's 1992 SBBI data from 1926 on, illustrated with 50% common stocks and 50% intermediate-term Treasuries; a 4% first-year withdrawal, raised for inflation, never exhausted a portfolio before 33 years, while 4.25% could fail in 28 years; 3% (and about 3.5%) never lasted less than 50 years; 5% is 'risky' and 6% or more is 'gambling'; recommended 50%-75% stocks; assumed tax-deferred accounts; a 1929 retiree who cut withdrawals 5% had 20% more wealth by 1949.
  4. [4]The Safe Withdrawal Rate Series · Karsten Jeske, Early Retirement Now, 2016-2025.The series models very long early retirements ("a 50 or even 60-year horizon"); withdrawal rates of 3.25-3.50% would have survived even the most catastrophic historical market conditions, and Part 3 argues about 3.25% is needed for low failure risk over 60 years when valuations are high.
  5. [5]The Ultimate Guide to Safe Withdrawal Rates, Part 1 · Karsten Jeske, Early Retirement Now, December 2016.A 4% rule with a 50/50 portfolio had about 95% success over 30 years but only about 65% over 60 years.
  6. [6]Historical Returns on Stocks, Bonds and Bills: 1928-2025 · Aswath Damodaran, NYU Stern School of Business, Updated January 5, 2026.Annual S&P 500, 10-year Treasury and CPI data used by our Monte Carlo and historical backtests (S&P 500: 10.02% a year nominal, 1928-2025).
  7. [7]Vanguard economic and market outlook: 10-year return forecasts · Vanguard, October 21, 2026 (as of September 30, 2026).10-year annualized nominal forecasts: US stocks 4.8%-6.8%, developed ex-US stocks 5.3%-7.3%, US bonds 5.1%-6.1%.
  8. [8]The Shockingly Simple Math Behind Early Retirement · Mr. Money Mustache, January 13, 2012.Assumes 5% returns after inflation, a 4% withdrawal rate, a starting net worth of zero and savings rate as a share of take-home pay (gross minus taxes, 401(k) deductions added back). A 10% savings rate means about 51 working years, 15% retires you 8 years earlier, and 50% means about 16.
  9. [9]Understanding sequence of return risk and safe withdrawal rates · Michael Kitces, Kitces.com, October 1, 2014.Real returns in the first decade of retirement largely determine the safe withdrawal rate (correlation about 0.79).
  10. [10]Guyton-Klinger guardrails: retirement income rules · Kitces.com, March 27, 2024.Guyton-Klinger rules (Tharp and Fitzpatrick): cut dollar withdrawals 10% if the withdrawal rate rises 20% above the initial rate, raise them 10% if it falls 20% below, skip the inflation adjustment when the trailing 12-month return is negative, and no guardrail cuts in the final 15 years of a plan; in Jeske's test a 1966 retiree starting at 4% saw withdrawals bottom out 59% lower; the authors argue the framework triggers cuts when they are not needed and tends to overcorrect, preserving far more capital than needed. Guyton-Klinger rules: cut dollar withdrawals 10% if the withdrawal rate rises 20% above the initial rate, raise them 10% if it falls 20% below, skip the inflation adjustment after a negative year, and no cuts in the final 15 years. In history the cuts were deep: a 1966 retiree starting at 4% cut withdrawals as low as $16,400 a year (59% below plan) and a 1965 retiree 54%; the authors propose risk-based guardrails instead.
  11. [11]How will the loss of enhanced premium tax credits affect older adults? · KFF, February 26, 2026.Enhanced ACA subsidies expired at the end of 2025, so the 400% of poverty-level subsidy cliff is back for 2026. With the enhanced credits expired, income at 401% of poverty ($62,757 for one person in 2026) gets no subsidy. A 60-year-old earning $65,000 (415% of poverty) faces a national average benchmark silver premium of $15,914 a year in 2026, $10,389 more than under the enhanced credits. The enhanced ACA premium tax credits expired on December 31, 2025, so enrollees above 400% of the poverty level get no assistance; a 60-year-old earning $65,000 (415% of poverty) pays $10,389 more a year toward a benchmark premium. With enhanced credits expired, enrollees above 400% of poverty get no premium tax credit in 2026; unsubsidized 2026 national average premiums for a 60-year-old are $11,625 (lowest-cost bronze) and $15,914 (benchmark silver); Marketplace premiums for older adults can be up to three times those of younger enrollees.
  12. [12]Social Security Retirement Benefits: Claiming Ages (R47151) · Congressional Research Service, June 8, 2022.Full retirement age is 67 for people born in 1960 or later; claiming at 62 cuts benefits 30%; delayed credits add 8% a year up to 70 (24% more at 70 when full retirement age is 67); workers with 35 or more years of covered earnings lose little of their basic benefit by stopping work early (p. 24). Pages 5-6: someone entitled to their own benefit and a spousal or survivor benefit in effect receives the higher of the two; at full retirement age a spouse can receive 50% of the worker's benefit, with no delayed retirement credits; a widow(er) claiming at full retirement age or later can receive 100% of the deceased worker's benefit. At full retirement age a spouse can receive 50% of the retired worker's benefit, reduced if claimed earlier (32.5% at 62 when FRA is 67), with no delayed retirement credits (p. 6); a widow(er) claiming at FRA or later can receive 100% of the deceased worker's benefit (p. 7); a dually entitled person receives the higher of their own and the spousal or survivor benefit (p. 6).
  13. [13]Consumer Expenditure Surveys, Table 1300: Age of reference person, annual expenditure means, 2025 · US Bureau of Labor Statistics, 2026.Average annual expenditures in 2025 by age of reference person: all consumer units $81,905; under 25 $54,136; 25-34 $78,579; 35-44 $93,650; 45-54 $106,658; 55-64 $85,442; 65 and older $64,445 (65-74 $69,333, 75 and older $57,959). Healthcare: $6,470 for all units, $7,317 at 55-64 and $7,986 at 65 and older. Personal insurance and pensions: $10,175 for all units, $15,075 at 45-54 and $3,550 at 65 and older. 2025 mean yearly spending, households 65+ vs all households: total $64,445 vs $81,905; shelter $13,992 vs $17,626; food $8,226 vs $10,633; transportation $10,109 vs $13,492; healthcare $7,986 vs $6,470; utilities, fuels and public services $4,680 vs $4,931; entertainment $2,975 vs $4,084; average household size 1.7 vs 2.4 people.
  14. [14]Consumer Expenditure Surveys glossary · US Bureau of Labor Statistics, Ongoing.Personal insurance and pensions includes retirement, pensions and Social Security; that part includes all Social Security contributions paid by employees and employee contributions to government and private pension programs and retirement programs for the self-employed. Personal insurance and pensions covers life and other personal insurance plus retirement, pensions and Social Security contributions; expenditures include sales and excise taxes, while personal income taxes are reported separately.
  15. [15]Real Personal Consumption Expenditures and Real Personal Income by State, 2024 · US Bureau of Economic Analysis, February 19, 2026.Regional price parities express each state's price level as a percentage of the national level; in 2024 the highest were California 110.7, Hawaii 110.0 and New Jersey 108.8, and the lowest Arkansas 86.9, Mississippi 87.0, and Iowa and Oklahoma 87.8.
  16. [16]Federal poverty level (FPL) · HealthCare.gov (Centers for Medicare & Medicaid Services), Checked November 11, 2026.Poverty guidelines: $15,650 for one person and $21,150 for two in 2025; $15,960 and $21,640 in 2026. The previous year's guidelines are used for the next year's Marketplace savings; incomes between 100% and 400% of the poverty level qualify for the premium tax credit. 2026 poverty guidelines: $15,960 for one person and $21,640 for two; incomes between 100% and 400% of the poverty level qualify for the premium tax credit in all states; below 138% you may qualify for Medicaid if your state expanded it; below 100% you probably won't qualify for Marketplace savings. 2026 Marketplace savings are based on the 2025 poverty guidelines: $15,650 for one person and $21,150 for two.
  17. [17]What's included as income · HealthCare.gov (Centers for Medicare & Medicaid Services), Checked November 11, 2026.Marketplace income (MAGI) includes most IRA and 401(k) withdrawals, capital gains and all Social Security benefits, but not qualified distributions from a designated Roth account.
  18. [18]9 things to watch for the 2027 ACA open enrollment period · KFF, November 6, 2026.For 2027 coverage, people with incomes above 400% of the poverty level still get no premium tax credit; open enrollment started November 1, 2026 in most states; average benchmark silver premiums rise 13%.

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