Lean FIRE Calculator — United States

The default here is $35,000 a year in today's dollars. There is no official line for "lean"; it usually means living deliberately below the typical household's spending, with housing, transport and health care doing most of the work.

Building the budget from your own spending gives a more reliable number than any benchmark. Two lines are easy to miss in a lean plan: health insurance before Medicare at 65, and irregular costs such as car replacement and home repairs.

A lean retiree's income is often low enough to make Marketplace coverage much cheaper, because premium tax credits rise as income falls (HealthCare.gov). With the enhanced credits expired at the end of 2025, and unless Congress restores them, eligibility is limited to household incomes between 100% and 400% of the federal poverty level.

Very low incomes can fall outside the credits altogether: in states that expanded Medicaid, they may qualify for Medicaid instead, while in states that did not, income below 100% of the poverty level can leave a gap. Rules vary by state and are changing, so check them for your state before building a lean plan around a particular income.

A lean retiree usually has a long horizon and little spending that could be cut in a bad year, so this page starts at 3.5% instead of 4%. At 3.5%, the target is about 28.6 times annual spending: $1,000,000 for $35,000 a year, against $875,000 at 4%.

The rate only sets the headline target. Whether the plan lasts is tested year by year to your plan-to age, so you can try 4% and see whether the projection still holds.

Long-term capital gains and qualified dividends are taxed at 0%, 15% or 20% depending on taxable income, and the standard deduction ($16,100 for a single filer in 2026) comes off first (IRS). A lean retiree living off a brokerage account may pay little or no federal income tax on it. The calculator's default withdrawal tax rate of 8% may therefore be on the high side for a lean plan, and you can lower it under Assumptions.

Housing is the biggest swing factor in a lean budget. Owning a home outright removes rent or a mortgage, leaving property tax, insurance and maintenance; renting keeps a cost that tends to rise with the local market. Where you live matters as much: the same lifestyle costs very different amounts in a high-cost city and a lower-cost region, and state income tax ranges from nothing to several percent.

The calculator applies a flat state tax rate that you set, and treats a mortgage as an expense that ends when the loan is paid off, under Other income & expenses. Both make a visible difference to a lean plan's FIRE age.

A lean budget is the one Social Security covers the largest share of. Even a reduced benefit, because retiring early leaves zero years in the 35-year average, can cover much of a lean budget from the late sixties. Add your own estimate under Other income & expenses to see how much less the portfolio has to carry.