Lean / Regular / Fat — which one are you?
Lean FIRE: retire on $25-40k/yr of spending. Typical net worth target: $600k-1M. Works for low-COL areas, paid-off home, no kids in private school. Regular FIRE: $50-80k/yr spend, $1.25-2M target — the bullseye for most US dual-income households. Fat FIRE: $150k+ /yr spend, $3.75M+ target. Common for HENRY (high-earner-not-rich-yet) tech and finance folks who want to keep travel + lifestyle inflation intact.
Coast FIRE — the underrated milestone
Coast FIRE is the dollar amount that, if invested today and left alone with no further contributions, would grow to your full FIRE number by your target retirement age. Once you hit it, you can downshift to lower-paying / more meaningful work, take a sabbatical, or just stop maxing retirement accounts. Most high earners reach Coast FIRE 10-15 years before regular FIRE.
Why the 4% rule deserves a haircut in 2025
The Trinity Study used 30-year retirements. FIRE retirees often need 40-50 year horizons. At today's CAPE ratios (>30 for the S&P), sequence-of-returns risk in the first decade is the dominant failure mode — a 30-40% market drop in year 1-2 of retirement can permanently impair a 4% withdrawal. Pulling SWR to 3.25-3.5% adds ~15-25% to your FIRE number but pushes long-horizon survival rates close to 100% historically.
What this calculator does NOT model
Sequence-of-returns risk, healthcare in the gap before Medicare (typically $12-20k/yr per adult on ACA), Social Security (most FIRE planning conservatively assumes zero), tax drag on withdrawals from taxable accounts, real estate / business equity, and lifestyle inflation between now and your FIRE date. Build a 10-20% buffer on top of the math here for any of these.
FAQ
What's the difference between Lean, Regular, and Fat FIRE?
All target multiples of annual spending. Lean = 25× a frugal $25-40k. Regular = 25× a comfortable $50-80k. Fat = 25× a high-end $150k+. Same math, different lifestyle assumption. There's also Barista FIRE (semi-retire with part-time work) and Coast FIRE (have enough invested today that you don't need to save more).
Is the 4% rule still safe?
Mostly yes, with caveats. The original Trinity Study (1998, updated 2009-2018) tested 30-year retirements; survival rates were 95-100% for a 50/50 stocks/bonds portfolio. For 40-50 year FIRE retirements at today's valuations, most researchers recommend 3.25-3.5% as the modern safe rate. Use 4% if you have flexibility to cut spending in down years, 3.25-3.5% if not.
What real return should I use?
The S&P 500's long-run real (inflation-adjusted) return is ~6.5-7%. A 90/10 stocks/bonds portfolio averages 5.5-6.5% real. A 60/40 portfolio averages 4.5-5.5% real. Use 5% if you want conservative, 6% if you want consensus, 7% if you want optimistic. Higher than 7% real and you're projecting outsized performance.
Does Coast FIRE include Social Security?
Most FIRE calculators (this one included) ignore Social Security. If you've worked 35 years of substantial earnings, you'll likely receive $25-50k/yr in Social Security at full retirement age — that reduces the portfolio you need by $625k-1.25M at a 4% rule. Use SSA.gov estimates to refine your number.
How does healthcare fit into the FIRE number?
It's the single biggest variable in early retirement. ACA marketplace coverage runs $400-900/mo per adult depending on age, state, and subsidies. Subsidies phase out around $58k MAGI for a single filer (2025) and ~$78k for a couple. Many early retirees keep MAGI low intentionally to stay subsidy-eligible. Budget $10-20k/yr/adult for healthcare in the gap to Medicare at 65.
Should I include my house in my FIRE number?
Only if you plan to sell it. The FIRE number is what you need in investable, withdrawal-eligible assets. Your primary residence reduces spending (no rent/mortgage in retirement) but doesn't fund withdrawals. Some FIRE planners include a 'downsizing dividend' if they intend to sell and move to a lower-COL area in retirement.
What's the difference between real and nominal returns?
Real = after inflation. Nominal = before inflation. Use real returns when your annual-spend input is in today's dollars (which it should be — you don't budget 2055 dollars). The S&P's nominal long-run return is ~10%; real is ~6.5-7% after taking out the historical 3% inflation drag.
What's sequence-of-returns risk?
A 30% market drop in years 1-3 of retirement is far more dangerous than the same drop 15 years in — because you're selling assets at depressed prices to fund spending. Two retirees with identical 30-year average returns can have wildly different outcomes based purely on the order of returns. Mitigations: bond tent (high bonds % at retirement start, declining over time), 1-3 year cash buffer, flexible spending rule (cut spending in down years).
Can I FIRE on real estate instead of stocks?
Yes, with caveats. Net rental yield (after vacancy, capex, management, taxes, insurance) typically runs 4-7% — comparable to a 4% SWR. But real estate isn't passive (even with PM), concentrates risk geographically, and is hard to scale beyond a handful of doors. Most successful real-estate-FIRE portfolios are a mix: paid-off rentals for cash flow + index funds for liquidity.
What's a 'just one more year' problem?
The pattern of FIRE-eligible savers who keep working past their FIRE number because the next year always feels safer than retiring. Worth being aware of — if the math says you're FIRE-ready and you're still going, be honest about whether it's risk management or fear of identity loss.
How this calculator is built
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Written by Sam Doshi and the RevenueLab editorial team. We don't sell the data feeds this tool is built on.
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Last reviewed
June 2026. We re-check every figure on the platform on a rolling quarterly cycle.
Editorial standards
See our editorial policy and disclaimer. Results are estimates, not advice.