How Much Do You REALLY Need to Never Work Again?
Andrei Jikh's viral question — "How much money do you REALLY need?" — maps directly to your Financial Independence Number: the portfolio size at which investment returns cover all expenses. The 4% rule (25x annual expenses) is the baseline, but real planning needs adjustments for healthcare before Medicare, sequence risk, inflation, and whether you want lean, regular, or fat FIRE. This calculator gives you your exact number across multiple withdrawal strategies.
About This Calculator: Financial Independence Number
Why: Everyone asks "How much do I need to retire?" — but the real question is "How much do I need to never work again?" The FI number answers that with the 4% rule, Social Security offset, healthcare gap, and lean vs. fat FIRE options.
How: Enter your monthly essential and discretionary expenses, target FI age, Social Security expectations, and healthcare costs. The calculator computes your FI number at 3%, 3.5%, and 4% withdrawal rates, plus lean/fat variants and gap analysis.
📋 Quick Examples — Click to Load
📊 FI Number by Withdrawal Rate
Your FI number at 3%, 3.5%, and 4% withdrawal rates
📈 Portfolio Survival (Simplified)
Approximate success probability over 40 years at your withdrawal rate
🍩 Expense Breakdown
Essential vs. discretionary vs. one-time annual spending
📉 Gap Analysis: Current Savings vs. FI Number
Projected savings growth (6%) vs. your FI number target
⚠️For educational and informational purposes only. Verify with a qualified professional.
Andrei Jikh's question "How much money do you REALLY need?" maps directly to your Financial Independence Number — the portfolio size at which investment returns cover all expenses. The 4% rule (25x annual expenses) is the baseline, but real planning requires adjustments for healthcare before Medicare, sequence-of-returns risk, inflation, and whether you want lean, regular, or fat FIRE. The Trinity Study found 4% withdrawal had ~95% success over 30 years; Early Retirement Now and Kitces.com recommend 3.5% for longer retirements.
Sources: Trinity Study (Cooley, Hubbard, Walz), Early Retirement Now, Kitces.com.
Key Takeaways
- • Your FI number = Annual Expenses ÷ Withdrawal Rate. At 4%, that's 25x annual expenses — the most widely used benchmark.
- • Lean FIRE (essentials only) can cut your number by 40–50% vs. regular FIRE; Fat FIRE (luxury lifestyle) can double or triple it.
- • Social Security reduces the portfolio you need: each $1,000/month in benefits ≈ $300K less at 4% withdrawal.
- • Healthcare before 65 is a major cost — budget $800–$1,500/month per couple and multiply by years until Medicare.
Did You Know?
How Does FI Number Calculation Work?
Annual Expenses
Sum your monthly essential (housing, food, insurance, transport), monthly discretionary (travel, dining, hobbies), and annual one-time expenses (vacation, gifts, maintenance). Multiply monthly by 12 and add one-time.
Withdrawal Rate
4% = 25x expenses. 3.5% = 28.6x (more conservative). 3% = 33.3x (very safe). Lower rates increase your FI number but improve portfolio survival probability over long retirements.
Social Security Offset
Your expected monthly benefit × 12 ÷ withdrawal rate = portfolio equivalent. Subtract this from your FI number to get the amount you need to fund before claiming age.
Expert Tips
FI Number by Spending Level (4% Rule)
| Monthly Spend | Annual | FI Number (4%) | Style |
|---|---|---|---|
| $2,500 | $30K | $750K | Lean FIRE |
| $5,000 | $60K | $1.5M | Regular FIRE |
| $8,000 | $96K | $2.4M | Family FIRE |
| $15,000 | $180K | $4.5M | Fat FIRE |
Frequently Asked Questions
What is the 4% rule?
The 4% rule, from William Bengen's 1994 research and the Trinity Study (Cooley, Hubbard, Walz), states that you can withdraw 4% of your portfolio in year one of retirement and adjust for inflation each year, with a high probability of not running out of money over 30 years. It implies your FI number = 25x annual expenses (100 ÷ 4 = 25).
What is the FI number?
Your Financial Independence (FI) number is the portfolio size at which investment returns can cover all your living expenses indefinitely. It answers "How much do I need to never work again?" The classic formula: FI Number = Annual Expenses ÷ Withdrawal Rate. At 4%, that's 25x annual expenses.
Is 4% still safe?
Early Retirement Now and Kitces.com research suggests 4% remains reasonable for 30-year retirements, but early retirees (40+ year horizons) may want 3.5% or 3% for added safety. Sequence-of-returns risk — poor returns in early retirement — can reduce success rates, so many planners use 3.5% for extra cushion.
Lean vs Fat FIRE?
Lean FIRE covers only essential expenses (housing, food, insurance) — typically $30K–$40K/year, FI number ~$750K–$1M. Fat FIRE includes luxury travel, dining, and hobbies — often $100K+/year, FI number $2.5M+. Your choice depends on lifestyle goals and willingness to trade years of work for spending flexibility.
What about healthcare?
Before Medicare at 65, healthcare is a major cost. ACA marketplace plans average $500–$1,200/month per person. Budget $800–$1,500/month for a couple. The calculator includes a healthcare gap cost: estimated monthly premium × 12 × years until Medicare, which you should add to your FI number or fund from a separate reserve.
How does Social Security affect FI?
Social Security reduces the portfolio you need. Each $1,000/month in expected benefits (at claiming age) is equivalent to ~$300K in portfolio value at 4% withdrawal ($12K ÷ 0.04). If you retire at 50 and claim at 67, you need to fund 17 years from portfolio alone before SS kicks in.
Key Statistics
Official Data Sources
⚠️ Disclaimer: This calculator provides estimates based on historical withdrawal rate research. Actual results depend on investment returns, inflation, spending changes, and longevity. The 4% rule is a guideline, not a guarantee. Consult a fiduciary financial advisor for personalized planning. Healthcare costs, taxes, and Social Security rules may change. This is not financial advice.