How Coast FIRE Works
Coast FIRE means reaching a point where your portfolio will grow to your full FIRE number by retirement age, even if you stop contributing at that point. This calculator shows both your true Coast FIRE number today and what happens if you keep contributing each month until your chosen age.
Your full FIRE number is based on your expected retirement spending and withdrawal rate. On this page, annual return is treated as a real return assumption, so you do not need a separate inflation field. The first result box shows the amount you would need invested today to stop contributing immediately, while the status and projected portfolio also take your monthly contributions into account.
If you want to model the impact of your income and spending habits first, try the Savings Rate Calculator. If you want to model continued investing instead of coasting, try the FIRE Calculator. If you want to estimate the portfolio your spending supports, use the 4% Rule Calculator. If you want to project pure growth over time, try the Compound Interest Calculator.
What This Calculator Is Good For
- Checking whether your current portfolio is already large enough to Coast FIRE
- Estimating your Coast FIRE number with a simpler real-return assumption
- Estimating how far away you are from the point where new contributions become optional
This view helps you compare your current portfolio, your ongoing monthly contributions, and your retirement spending target. Use it to see whether you are already on a Coast FIRE path, whether you would reach it later than planned, or how much more you would need to invest to hit your chosen age.