What Is FIRE? Financial Independence, Retire Early Explained
A complete guide to the FIRE movement: FIRE number, savings rate, 4% rule, and Lean/Fat/Coast FIRE variations.
FIRE means saving enough that investments cover your living costs — your target is roughly annual expenses × 25, and your savings rate, not your returns, decides how fast you get there.
What you'll walk away with
Skim these first — then dig into the details below.
- 1FIRE number = annual expenses × 25 using the 4% safe withdrawal rate.
- 2Savings rate matters more than investment returns in your first decade.
- 3Lean FIRE targets minimal expenses; Fat FIRE allows a comfortable lifestyle.
- 4Coast FIRE means investments will grow to your target without new contributions.
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FIRE — Financial Independence, Retire Early — is one idea with a lot of branding: build a portfolio large enough to cover your expenses, and paid work becomes optional.
See your years to independence at your current savings rate in the FIRE calculator.
Calculate your FIRE number
The formula is the 4% rule applied to your own spending, not your income.
- 1
Total your actual annual expenses, including insurance, taxes, and irregular costs.
- 2
Multiply by 25 for the standard 4% target.
- 3
Multiply by 28–33 for a conservative 3–3.5% target if you plan a 40+ year retirement.
- 4
Subtract any pension or future Social Security you are comfortable counting on.
Savings rate is the real lever
In your first decade, contributions dwarf compounding — you simply do not have enough invested for returns to matter much yet. That makes savings rate the variable worth optimizing.
Moving from a 20% to a 40% savings rate roughly halves the timeline, because you invest more and need less.
- Savings rate = (income − spending) ÷ income, calculated after taxes.
- 10–15% is conventional retirement pace; 30%+ is FIRE territory.
- Housing and transportation are where large, permanent cuts live.
- Raises are the cheapest source of savings if you bank them before adjusting your lifestyle.
The FIRE variations, decoded
The labels describe different tradeoffs between target size and how soon you stop working.
- Lean FIRE: $25k–$40k annual spending, smallest target, least margin for surprises.
- Fat FIRE: $80k+ spending with a comfortable lifestyle and a much larger target.
- Coast FIRE: enough invested that ordinary growth reaches your number by traditional retirement age, so you stop contributing and just cover current bills.
- Barista FIRE: part-time work covers essentials — often for health insurance — while investments keep compounding.
Risks worth planning around
A 45-year retirement has to survive things a 25-year retirement never sees.
- Sequence risk: a crash in your first few years does lasting damage.
- Health insurance: ACA subsidies depend on income, so your withdrawal strategy affects your premiums.
- Access: money in a 401(k) before 59½ needs a Roth ladder or SEPP plan.
- Inflation: your target must grow with prices — see how inflation erodes savings.
Start this month
Four steps that move the date closer.
- 1
Calculate your current savings rate honestly.
- 2
Set your FIRE number and run the timeline in the FIRE calculator.
- 3
Fill tax-advantaged space first — see 401(k) vs IRA.
- 4
Compare your progress against financial milestones by age.
Disclaimer: This page includes AI-assisted educational content reviewed for general accuracy. It is not personalized financial, tax, or legal advice. Verify numbers with a qualified professional and our editorial standards.
Continue reading
Related guides that deepen the same decision.
How Much Do You Need to Retire? Rules, Formulas & Examples (2026)
Estimate the annual spending your portfolio must cover after Social Security and pensions, then multiply that number by 25 — that is your starting nest-egg target.
ReadRetirement401(k) vs IRA: Where Should You Save for Retirement First?
Contribute enough to your 401(k) to capture the full employer match, then max an IRA, then go back and fill the rest of your 401(k) — the match is the only guaranteed return you will ever get.
ReadPersonal FinanceFinancial Milestones by Age: A Complete Checklist
A common benchmark is 1x your salary saved by 30, 3x by 40, 6x by 50, and 8–10x by 60 — with an emergency fund and no high-interest debt as the foundation underneath.
ReadReady to plug in your numbers?
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