Financial Independence Age Calculator
Calculate when you can retire based on your savings rate, spending, and the 4% rule.
Who This Is For
Anyone who wants to know when they can stop working for money. Whether you're pursuing early retirement (FIRE) or traditional retirement, this calculator shows your path based on current savings and spending.
Example Scenario
You're 30 years old with $50,000 invested. You invest $1,500/month and spend $40,000/year. Your FI number is $1,000,000 (25× spending).
Result: At 7% returns, you could reach financial independence around age 47.
How It Works
This calculator uses the withdrawal rate method:
- FI Number = Annual Spending ÷ Withdrawal Rate (e.g., $40,000 ÷ 4% = $1,000,000)
- Monthly simulation: Starting from your current portfolio, add monthly contributions and compound growth
- FI Age: When your portfolio reaches the FI Number
The milestones show your progress at 25%, 50%, 75%, and 100% of your FI Number—because even partial financial independence gives you more options and freedom.
Assumptions and Formula
Assumptions used in this model:
- Withdrawal rule remains constant (for example, 4%).
- Portfolio returns and monthly contributions are constant.
- Spending target is stable in nominal terms unless adjusted manually.
FI target formula: FI number = annual spending ÷ withdrawal rate. The model compounds your portfolio monthly until it crosses the FI number.
How to Interpret Your Results
| Signal | What It Means | Action |
|---|---|---|
| FI age shifts significantly with +1% return | Projection is return-sensitive | Track conservative and base scenarios |
| Small spending cut moves FI date forward | FI number is dominated by annual spend | Optimize recurring expenses first |
| Contribution increases beat market assumptions | Savings rate is your strongest lever | Automate raise-based contribution bumps |
Educational tool, not financial advice. The 4% rule is a guideline, not a guarantee. Actual returns, inflation, and tax situations vary. Consult a financial advisor for personalized retirement planning.
Frequently Asked Questions
Deep Dive Guide
Read the Financial Priority Ladder guide
Use FI planning after emergency fund and high-interest debt priorities are handled.