Lean FIRE Calculator
Lean FIRE means retiring on less — a frugal budget that dramatically shrinks the portfolio you need and pulls your retirement date forward. Set your frugality factor to see how cutting spending changes your number.
Your Numbers
Lean retirement spending as % of current expenses. 60% is the classic Lean FIRE benchmark.
What is Lean FIRE?
Lean FIRE is early retirement on a deliberately frugal budget. While standard FIRE replicates your current spending in retirement, Lean FIRE targets a significantly smaller annual figure — often through geographic arbitrage, minimalism, or eliminating major expense categories like car ownership or frequent dining out.
The main appeal is a dramatically smaller required portfolio. At a 60% frugality factor and 4% withdrawal rate, a Lean FIRE number is just 15× current expenses (versus 25× for standard FIRE). That can shave a decade or more off the accumulation phase, especially if combined with a high savings rate.
The tradeoff is a tight margin for error. A lean budget doesn't absorb large unexpected expenses well — healthcare emergencies, home repairs, or supporting an adult child can create real stress. Many Lean FIRE practitioners plan some flexible income (a side project, occasional consulting) to bridge gaps, which is essentially a move toward Barista FIRE.
For Lean FIRE, many planners prefer a slightly lower withdrawal rate — 3–3.5% — to build in resilience over a potentially 50+ year retirement. The calculator defaults to 4%, but try 3.5% to see the more conservative number.
Frequently Asked Questions
What is Lean FIRE?
Lean FIRE is early retirement on a frugal, minimalist budget — typically 50–65% of your current expenses or an absolute figure under $40,000 per year. The appeal is a dramatically smaller required portfolio and a much earlier retirement date. Many Lean FIRE adherents relocate to lower cost-of-living areas, grow their own food, or embrace a simple, low-consumption lifestyle.
How much do you need for Lean FIRE?
Using the 4% rule, Lean FIRE requires 25× your target annual spending in retirement. If you plan to live on $30,000 per year, your Lean FIRE number is $750,000. At $25,000/year, you need $625,000. Because the target spending is lower, Lean FIRE portfolios are typically 40–60% smaller than standard FIRE — meaning you can retire years earlier.
How is Lean FIRE different from standard FIRE?
Standard FIRE replaces 100% of your current lifestyle spending. Lean FIRE targets a deliberately smaller annual budget, typically through geographic arbitrage, minimalism, or cutting major expense categories. The 60% frugality factor default in this calculator is an illustrative benchmark — there is no universally fixed percentage that defines Lean FIRE. What matters is choosing an honest, sustainable spending target you can actually live on for decades, then calculating the portfolio to fund it.
Can you really live well on a Lean FIRE budget?
Many people do. The Lean FIRE community is full of retirees who found that reducing consumption increased their life satisfaction — more time, less stuff, and freedom from work more than compensates for smaller spending. Key strategies: eliminate housing costs (own outright or geo-arbitrage), keep healthcare costs low (ACA subsidies, health-sharing plans), and find free or cheap hobbies. The risk is that unexpected expenses — healthcare, home repairs — can stress a lean budget.
What withdrawal rate is right for Lean FIRE?
Because lean budgets leave little margin for error, many Lean FIRE retirees use 3–3.5% rather than 4%, especially if retiring very early. A lower withdrawal rate means a slightly larger portfolio — but it dramatically reduces the risk of running out of money over a 40–50 year retirement. You can also use flexible withdrawal strategies: spend less in bad market years and more in good ones.