Coast FIRE Calculator
Calculate the exact net worth required today so compound interest funds retirement.
How to Use the Coast FIRE Calculator
Coast FIRE (Coast Financial Independence, Retire Early) is a milestone in the personal finance movement where you have accumulated enough invested capital at a young age that compound growth alone will fund your retirement without needing to save another dollar. Once you reach your Coast FIRE number, you only need to earn enough income to pay for your day-to-day living expenses.
Formula and Calculation Methodology
- 25× Rule: Safe withdrawal standard (4% rule) establishing total capital required at retirement
- r: Annual real compound return on equity investments adjusted for inflation (historically 6%–7%)
- t: Investment horizon in years between current age and target full retirement age
By decoupling your monthly budget from aggressive retirement savings rates, Coast FIRE unlocks unprecedented lifestyle flexibility decades before traditional retirement. Workers can transition to lower-stress careers, take parental leave, travel, work part-time, or launch creative businesses without sacrificing their long-term financial security. Our calculator uses the Trinity Study’s 4% rule and inflation-adjusted compound interest equations to determine your exact target.
Coast FIRE Targets by Age ($50,000/yr Spending, 7% Real Return)
| Current Age | Retirement Age 60 Target | Retirement Age 65 Target | Annual Freedom Impact |
|---|---|---|---|
| Age 25 | $118,500 | $84,500 | Can downshift career to part-time or passion work |
| Age 30 | $164,200 | $117,100 | Covers retirement; work only to cover living expenses |
| Age 35 | $230,300 | $164,200 | Eliminates need for further retirement contributions |
| Age 40 | $323,000 | $230,300 | Enables sabbatical, entrepreneurship, or lower-stress role |
| Age 45 | $453,000 | $323,000 | Compound interest does remaining heavy lifting |
Frequently Asked Questions
What is the difference between Coast FIRE and Barista FIRE?
Coast FIRE means your existing investments will grow to fund retirement, and you work any job to pay 100% of current living expenses. Barista FIRE involves taking a part-time job for health benefits while actively withdrawing a small percentage from portfolio dividends.
Does the Coast FIRE formula account for inflation?
Yes, by utilizing a ‘real return’ (typically 6% to 7% for broad index funds like the S&P 500 or Total Stock Market index rather than nominal 10%), all projected values are expressed in today’s purchasing power.
What if market returns are lower than 7%?
If long-term returns average 5% instead of 7%, you will need a larger Coast FIRE balance today. You can adjust the real return slider in our calculator to model conservative market scenarios.