What is FIRE?
The movement, the math, and what your FIRE number actually means.
FIRE stands for Financial Independence, Retire Early — a movement focused on saving and investing aggressively (typically 25–70% of income) so investment returns alone can cover your living expenses decades before traditional retirement age. Once your portfolio is large enough that the 4% safe withdrawal rate funds your annual spending, work becomes optional.
Your FIRE number is 25× your annual expenses — the portfolio target derived from the 4% rule and the 1998 Trinity Study. Reach it, and you are financially independent. This free FIRE calculator finds your exact number and projects how many years it will take based on your savings rate, expected real return, and inflation.
How the FIRE calculator works
Three classic personal-finance formulas combined into one projection.
The calculator combines three classic personal-finance formulas to project your journey to financial independence:
- FIRE number = annual spending ÷ withdrawal rate. The default 4% withdrawal rate gives the 25× rule (1 ÷ 0.04 = 25). For 40–50 year early retirements, 3.3%–3.5% is more conservative.
- Real return= nominal return adjusted for inflation (Fisher formula). All projections are shown in today's purchasing power so the retirement date is meaningful.
- Years to FI = the compound-growth solution given your current savings, monthly contributions, real return, and inflation-adjusted goal. Spending is grown by inflation each year so the goal stays accurate.
Asset allocation matters: stocks have historically returned ~7% real long-term, bonds ~1–2% real. The calculator lets you set custom return assumptions for each bucket and weights them by your stocks/bonds split.
How to use this FIRE calculator
Seven inputs, about a minute — no signup, no ads.
- 1
Enter your current age and current savings.
Total invested across retirement and taxable accounts.
- 2
Enter your monthly savings.
How much you contribute each month while still working.
- 3
Set your expected annual retirement spending.
In today's money — the calculator will adjust for inflation.
- 4
Choose a withdrawal rate (default 4%).
Lower = safer for very long retirements.
- 5
Set asset allocation and expected returns.
Stocks vs bonds, with custom return rates.
- 6
Add an inflation assumption.
Defaults to 0; ECB target is 2%, US average ~3%.
- 7
Read your FIRE number and target retirement age.
The chart shows your portfolio trajectory year-by-year.
FIRE variants: Lean, Fat, Coast, and Barista
Different FIRE flavors fit different lifestyles — pick the target that matches yours.
Lean FIRE
Frugal early retirement on $25,000–$40,000 per year. FIRE number ~$625,000–$1M.
Fat FIRE
Comfortable early retirement on $100,000+ per year. FIRE number $2.5M+.
Coast FIRE
Already saved enough that compound growth alone funds retirement — no further contributions required.
Coast FIRE Calculator →Barista FIRE
Semi-retire with part-time or flexible work covering daily expenses while investments compound.
Common questions about FIRE
The questions readers ask most — answered briefly here, in depth in the Knowledge Base.
What savings rate do I need to retire early?▾
Roughly: 10% → 43 years to FI; 25% → 32 years; 50% → 17 years; 70% → ~8.5 years. Your savings rate matters more than your income — the math works the same at any income level.
How do I calculate my FIRE number?▾
Multiply your expected annual retirement spending by 25 (the 25× rule). $50,000 × 25 = $1,250,000. For 40–50 year retirements, multiply by 28–30 instead (3.3%–3.5% withdrawal rate).
What is the difference between Lean, Fat, Coast, and Barista FIRE?▾
Lean FIRE = frugal lifestyle, lower target. Fat FIRE = comfortable lifestyle, higher target. Coast FIRE = already saved enough to coast to retirement on compound growth. Barista FIRE = semi-retired with part-time income.
Is the 4% rule still valid in 2026?▾
Yes, as a baseline. For 30-year retirements it remains reliable. For early retirees with 40–50 year horizons, many planners recommend 3.3%–3.5% combined with flexibility — reducing withdrawals during market downturns.
Explore more tools & guides
Coast FIRE Calculator
How much do you need saved today to coast to retirement without saving another dollar?
📐The 4% Rule Explained
Where the rule comes from, how to calculate your FIRE number, and is it still valid in 2026?
📚FIRE Knowledge Base
In-depth guides on safe withdrawal rates, savings-rate math, sequence-of-returns risk, and FIRE variants.