FIRE Calculator — Financial Independence
Enter your annual expenses, current portfolio, and monthly savings to find your FI number, years to financial independence, and a portfolio growth chart.
7 %
1 %40 %
4.0 %
2 %6 %
FI Number (×25)
$900,000
Years to FIRE
16 years 6 months
Target year: 2043
Monthly Passive Income
$3,000
Achieved: 5.6 % Still needed: $850,000
Current portfolio: $50,000 $900,000
ⓘ Results are indicative only and do not constitute investment, financial, tax, or legal advice. Consult a qualified professional before making any financial decisions.
Related Calculators
How to use the FIRE calculator
- Annual retirement expenses — how much you need to spend per year in retirement
- Current portfolio — current value of your investments (ETFs, stocks, bonds, etc.)
- Monthly savings — how much you invest each month
- Real return — expected annual return after inflation (historically ~5–7% for equity ETFs)
- Safe withdrawal rate (SWR) — typically 4% (FI number = 25× annual expenses)
FI Number Formula
FI Number = Annual Expenses ÷ SWR
Common multipliers:
- SWR 4.0% → FI Number = expenses × 25
- SWR 3.5% → FI Number = expenses × 28.6
- SWR 3.0% → FI Number = expenses × 33.3
Years to FIRE Formula
n = ln((FN + S/r) / (P + S/r)) / ln(1 + r)
- FN = FI number
- P = current portfolio
- S = monthly savings
- r = monthly return (annual return ÷ 12)
- n = months to FIRE
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Worked Examples
Example 1 — Typical earner starting out
Annual expenses: $36,000 | Portfolio: $50,000 | Monthly savings: $2,000 | Return: 7% | SWR: 4%
- FI Number: $900,000
- Still needed: $850,000
- Years to FIRE: approximately 24 years
Example 2 — High savings rate
Annual expenses: $30,000 | Portfolio: $200,000 | Monthly savings: $5,000 | Return: 7% | SWR: 4%
- FI Number: $750,000
- Years to FIRE: approximately 8 years
- Monthly passive income: $2,500
Example 3 — Conservative Fat FIRE
Annual expenses: $60,000 | Portfolio: $500,000 | Monthly savings: $6,000 | Return: 6% | SWR: 3.5%
- FI Number: $1,714,000 (×28.6)
- Years to FIRE: approximately 13 years
Frequently Asked Questions
How safe is the 4% withdrawal rule really?
The Trinity Study showed a 4% SWR on a 50–75% stock portfolio survived 30 years in over 95% of historical US market scenarios. For a 40–50 year early retirement, many researchers recommend 3.5% or lower. Flexibility — reducing spending in down markets — dramatically improves survival rates for any SWR.
What is sequence of returns risk?
If markets crash in the early years of your retirement, large withdrawals at low prices can permanently deplete your portfolio even if long-run average returns are fine. Mitigations include holding 1–2 years of expenses in cash, flexible spending, or keeping a small income source in the early years.
Should I use nominal or real return?
Enter the real (inflation-adjusted) return. If you expect a 10% nominal return and 3% inflation, enter 7%. This way your expenses stay in today's dollars throughout the projection, which is much easier to reason about.
What if I'll have other income in retirement?
Any side income (part-time work, rental income, Social Security, pension) reduces the required withdrawal rate and improves portfolio safety. Barista FIRE explicitly plans for some earned income — this can dramatically lower the required FI number.
What investment vehicles are best for FIRE?
This calculator is vehicle-agnostic — use whatever fits your country and tax situation. Most FIRE practitioners favour low-cost broad index funds (e.g., total-world or S&P 500 ETFs), with tax-advantaged accounts (401k, IRA, ISA, etc.) maximised first. The key is low fees and broad diversification.