FIRE Calculator – Early Retirement & Financial Independence
Model your path to Financial Independence, Retire Early (FIRE). Adjust income, expenses, savings rate, investment returns, and withdrawal rate to see how many years it will take to reach your FIRE number.
FIRE Calculator
This is the lifestyle you want to fund when financially independent, in today’s dollars.
Real return = after inflation. Historically, a global stock-heavy portfolio might return ~4–6% real over long periods.
Common rule-of-thumb: 3–4% for long retirements (30+ years). Lower is safer but requires a larger portfolio.
Used only for optional nominal projections; the main FIRE math uses real (after-inflation) returns.
Key results
FIRE number (target portfolio):
$1,142,857
Years until FIRE:
18.4 years
Age at FIRE:
48.4 years
Savings & progress
Annual savings rate (of target spending): 45%
Current progress toward FIRE number: 4%
Tip: Increasing your savings rate usually has a bigger impact on FIRE date than chasing higher returns.
Simple projection (real dollars)
How this FIRE calculator works
FIRE stands for Financial Independence, Retire Early. The core idea is simple:
- Build an investment portfolio large enough that a small, sustainable withdrawal can cover your annual spending.
- Once your portfolio reaches that level (your FIRE number), you are financially independent.
1. FIRE number formula
Your FIRE number is the portfolio size needed to safely fund your desired annual spending:
FIRE number = Desired annual spending ÷ Safe withdrawal rate
In symbols:
\[ \text{FIRE number} = \frac{S}{r_w} \]
where:
- \(S\) = desired annual spending in retirement (in today’s dollars)
- \(r_w\) = safe withdrawal rate (as a decimal, e.g. 0.035 for 3.5%)
Example: If you want to spend $40,000 per year and choose a 3.5% withdrawal rate:
\[ \text{FIRE number} = \frac{40{,}000}{0.035} \approx 1{,}142{,}857 \]
2. Portfolio growth and time to FIRE
We assume you:
- Start with a current portfolio \(P_0\).
- Contribute a fixed amount each month \(C\) (in real, inflation-adjusted terms).
- Earn a constant real return \(r\) per year (after inflation).
We simulate year by year using a standard future value formula for contributions plus growth:
Approximate portfolio after \(t\) years with monthly contributions:
\[ P_t = P_0 (1 + r)^t + C \cdot 12 \cdot \frac{(1 + r)^t - 1}{r} \]
The calculator iterates year by year until \(P_t\) reaches or exceeds your FIRE number, or until it hits your maximum simulation years.
3. Savings rate and progress
We also compute:
- Annual savings = monthly contribution × 12.
- Savings rate (vs. target lifestyle) = annual savings ÷ target annual spending.
- Progress toward FIRE = current portfolio ÷ FIRE number.
Interpreting your FIRE results
Years until FIRE & age at FIRE
The calculator shows how many years it may take to reach your FIRE number and your approximate age at that point. This is a projection, not a guarantee.
Real-world outcomes will vary due to:
- Market volatility and sequence of returns risk.
- Changes in your income, savings, and spending.
- Taxes, fees, and unexpected life events.
Safe withdrawal rate (SWR)
The SWR is the percentage of your portfolio you plan to withdraw each year in retirement, adjusted for inflation. Common choices:
- 4% – classic “4% rule” from the Trinity Study (30-year horizon, US historical data).
- 3–3.5% – more conservative for very long retirements (40–50+ years) or risk-averse investors.
- 2–3% – very conservative; often used by ultra-cautious or very high net worth households.
Real vs. nominal returns
This calculator focuses on real (after-inflation) returns to keep everything in today’s dollars. If you expect 7% nominal returns and 2% inflation, your real return is about 5%.
How to reach FIRE faster
To move your FIRE date closer, you can:
- Increase your savings rate – earn more, spend less, or both.
- Lower your target retirement spending – choose a leaner lifestyle or geo-arbitrage.
- Work a bit longer – a few extra years can dramatically reduce risk.
- Invest efficiently – diversify, minimize fees and taxes, and stick to a long-term plan.
Limitations & assumptions
- Assumes constant real return and constant contributions.
- Ignores taxes, investment fees, and social security/pension income.
- Does not model sequence of returns risk or dynamic spending rules.
This tool is for education and planning only and is not financial advice. Consider consulting a qualified financial professional for personalized guidance.
Frequently asked questions about FIRE
Is the 4% rule safe for early retirement?
The 4% rule was based on 30-year retirements using historical US data. For very long retirements (40–50+ years), many planners suggest using a lower withdrawal rate (e.g. 3–3.5%) or flexible spending rules to reduce the risk of running out of money.
Should I include my home equity in my FIRE number?
Only include assets that can realistically be used to fund your spending. If you plan to downsize or use a reverse mortgage, some portion of home equity may count. Otherwise, many people treat their primary residence separately from their FIRE portfolio.
What if markets crash right after I reach FIRE?
This is called sequence of returns risk. To mitigate it, you can:
- Keep a cash or bond buffer (1–3 years of expenses).
- Use flexible spending rules (spend less after bad years).
- Consider part-time work or side income early in retirement.
How often should I update my FIRE plan?
At least once a year, or after major life changes (job change, move, marriage, children, etc.). Update your income, spending, portfolio value, and assumptions to keep your plan realistic.