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Lean FIRE vs Fat FIRE Calculator

Compare Lean, Regular, Fat and Barista FIRE side-by-side — see the trade-off between lifestyle and time freedom.

Updated May 2026 · Reviewed against current market data

Current age
18 yr70 yr
Current savings
$0$50.0 M
Monthly savings
$0$500 K
Expected annual return
Real (inflation-adjusted)
1%15%
Lean FIRE expenses / yr
Minimalist lifestyle
$0$5.0 M
Regular FIRE expenses / yr
Today's lifestyle
$0$5.0 M
Fat FIRE expenses / yr
Luxury lifestyle
$0$10.0 M
Part-time income / yr
Barista FIRE — reduces target
$0$500 K
Your earliest FIRELive
9.3 yr
Lean FIRESaving $3.0 K/mo on $150 K at 7% · 4% SWR
See full breakdown
FIRE spectrumLifestyle → Freedom
Lean
Minimalist
$750 K
Regular
Balanced
$1.3 M
Barista
Semi-retired
$875 K
Fat
Luxury
$3.0 M
Lean FIRE
Earliest
Minimalist · low cost of living
Portfolio target
$750 K
FIRE age
43
9.3 yr to go20%
Need / moOn track ✓
On track — current contribution covers this path.
Barista FIRE
Semi-retired · light part-time work
Portfolio target
$875 K
FIRE age
45
10.6 yr to go17%
Need / moOn track ✓
On track — current contribution covers this path.
Regular FIRE
Today's lifestyle · 4% rule
Portfolio target
$1.3 M
FIRE age
48
14.0 yr to go12%
Need / moOn track ✓
On track — current contribution covers this path.
Fat FIRE
Luxury · no compromises
Portfolio target
$3.0 M
FIRE age
58
23.9 yr to go5%
Need / moOn track ✓
On track — current contribution covers this path.

FIRE comparison table

Sorted by years to FIRE — fastest first.
FlavorTargetTimeAgeNeed / mo
Lean FIRE
Minimalist · low cost of living
$750 K9.3 yr43On track ✓
Barista FIRE
Semi-retired · light part-time work
$875 K10.6 yr45On track ✓
Regular FIRE
Today's lifestyle · 4% rule
$1.3 M14.0 yr48On track ✓
Fat FIRE
Luxury · no compromises
$3.0 M23.9 yr58On track ✓

Unified FIRE timeline

One portfolio · four milestones
The shaded curve is your projected portfolio. Each dashed line is a FIRE flavor's target. Dots mark the age you cross each one.
What if you tweak it?
  • +$600/mo (on top of your $3.0 K) moves Lean FIRE 1 year closer · Regular FIRE 1.2 yrs sooner.
  • Part-time income already lowers your Barista FIRE target by $375 K. Adding $7.5 K/yr more shaves another $188 K.
  • Your trajectory reaches Lean FIRE 14.6 years before Fat FIRE. That's the price of luxury.
Your next step

About the FIRE Flavors calculator

A FIRE strategy comparison dashboard. Calculate the target portfolio, FIRE age and required monthly savings for Lean FIRE ($25–35k expenses), Regular FIRE ($40–60k), Fat FIRE ($100k+) and Barista FIRE (part-time income offset) on a single screen — with a unified timeline chart and live what-if insights.

How it works

  1. 1
    Enter your savings & contributions
    Current investments, monthly contribution and an inflation-adjusted return (7% is the historical real return for the S&P 500). The same inputs feed all four FIRE paths.
  2. 2
    Set each lifestyle's target expenses
    Lean ($25–35k) is minimalist. Regular ($40–60k) is today's lifestyle. Fat ($100k+) is luxury. Barista uses your Regular target minus part-time income.
  3. 3
    Compare side-by-side
    The dashboard shows the portfolio target, FIRE age and required monthly contribution for each path, plus a unified timeline chart with all four milestones plotted on your single growth curve.
  4. 4
    Explore the trade-offs
    Watch what happens when you bump savings, lower Fat expectations, or add Barista income. Earlier freedom (Lean) vs higher spending (Fat) becomes immediately obvious.

This calculator is a planning tool, not financial advice. Results are projections based on the assumptions below — actual market returns vary. See the Methodology page for full editorial standards and data sources.

Return rate source
S&P 500 inflation-adjusted (real) long-run average (~7%), from Prof. Robert Shiller's Yale dataset. The same rate is applied to all four FIRE flavors.
Safe withdrawal rate (SWR)
4% for all flavors (Trinity Study, 1998). Portfolio target = Annual Expenses × 25. Barista FIRE target = (Annual Expenses − Part-time Income) × 25.
Compounding frequency
Monthly (12× per year). Portfolio grows at r/12 each month while contributions are added.
Tax treatment
Not modelled. All expense figures and Barista income are treated as post-tax amounts. In practice, part-time income may be subject to income tax.
Not accounted for
Differences in investment risk between lifestyle tiers, healthcare cost changes at different spending levels, or tax optimisation strategies per flavor.

Frequently asked questions

  • Lean FIRE is financial independence with a minimalist budget — typically $25,000–$35,000 in annual expenses. At 4% SWR that's a portfolio of $625k–$875k. It's the fastest path to FIRE but requires a frugal post-retirement lifestyle.

  • Fat FIRE targets a premium, no-compromise retirement — typically $100,000+ in annual expenses and a portfolio of $2.5M+. It takes the longest to reach but funds international travel, premium healthcare, and no lifestyle restrictions.

  • Barista FIRE is Regular FIRE minus part-time income. The canonical example is a barista with employer-subsidised insurance: a smaller part-time paycheck (~$15k/yr) covers the gap so the portfolio only needs to fund the rest. At 4% SWR, $15k of part-time income reduces your target by $375k.

  • Regular FIRE means a portfolio large enough to fund your current lifestyle ($40k–$60k typical) at a 4% safe withdrawal rate — usually $1M–$1.5M. It's the middle path between Lean's frugality and Fat's luxury.

  • Most FIRE seekers don't have a fixed target; they have a budget for each lifestyle. Comparing all four on one screen shows the real trade-off: every $10k of lifestyle inflation costs you $250k of portfolio (at 4% SWR) and roughly 2–3 extra working years.

  • 4% — the Trinity Study default, equivalent to 25× annual expenses. More conservative early retirees use 3.5% (≈ 28.6×); a leaner / shorter-horizon plan can use 5% (= 20×).

  • We simulate your portfolio month by month: your current savings grow at the return rate while monthly contributions are added. Years-to-FIRE for each flavor is the first month the portfolio crosses that flavor's target number.

  • Lifestyle inflation is the tendency for expenses to grow as income grows. The bigger your assumed retirement lifestyle, the larger your FIRE number — and every $1 of additional ongoing spend adds $25 to the portfolio you need.

Sources

All FIRE calculations on this site are grounded in peer-reviewed academic research and long-run historical data. See the Methodology page for full editorial standards.

  1. [1]Cooley, Hubbard & Walz (Trinity Study). Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable (1998, updated 2011)
  2. [2]Prof. Robert Shiller, Yale University. S&P 500 Historical Annual Returns (inflation-adjusted, 1871–present) (ongoing)
  3. [3]William P. Bengen. Determining Withdrawal Rates Using Historical Data (1994, Journal of Financial Planning)
  4. [4]Wade D. Pfau. Safe Savings Rates: A New Approach to Retirement Planning over the Life Cycle (2011, Journal of Financial Planning)
  5. [5]Michael Kitces. The Ratcheting Safe Withdrawal Rate — A More Dominant Version of the 4% Rule (and earlier SWR analysis for early retirees) (2012, Nerd's Eye View)

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