Coast FIRE is a milestone where you have invested enough that, with no further contributions, growth alone should carry your portfolio to your retirement goal by a traditional retirement age. Reaching it does not mean you stop working, but it means you no longer have to save for retirement. This can free up income and dramatically reduce financial pressure.
What Coast FIRE actually means
Coast FIRE is the point at which your existing investments, left untouched, will compound into your full retirement number by the time you reach your target age. Once you hit it, you only need to earn enough to cover current living expenses, not to keep funding retirement. Your nest egg is on autopilot, coasting to the finish line on growth alone. It is a partial form of financial independence rather than full early retirement.
The math behind the number
To find your Coast FIRE number, take your target retirement nest egg and discount it back to today using an expected real rate of return over the years remaining. The more years you have until retirement, the smaller the amount you need today because compounding does more of the work. This is why hitting Coast FIRE young is so powerful. The calculation rests on assumptions about returns and your future spending, so it is an estimate, not a guarantee.
Why it appeals to many savers
Coast FIRE offers much of the psychological benefit of financial independence without requiring an extreme savings rate for decades. After reaching it, you can shift to lower-paying but more fulfilling work, go part-time, or take career risks. The freed-up money that once went to retirement savings can fund travel, hobbies, or family life today. It reframes early saving as buying future flexibility rather than an all-or-nothing race to quit work.
Cautions and assumptions
Because Coast FIRE depends on decades of assumed growth, a prolonged period of weak returns could leave you short of the goal. It also assumes you can reliably cover living costs without saving more, which may falter during job loss or rising expenses. Building in a margin of safety, and revisiting the plan periodically, guards against these risks. Many people keep contributing at least a little even after reaching the milestone.
A 30-year-old wants 1.5 million dollars by age 65 and assumes a 5 percent real return. Discounting that goal back 35 years gives a Coast FIRE number of roughly 272,000 dollars. Once they have that invested, they could stop retirement contributions and let it coast.
Key takeaways
- Coast FIRE means growth alone should reach your retirement goal without new contributions.
- You still work to cover current expenses but no longer need to save for retirement.
- The number is your future goal discounted to today by an expected rate of return.
- It relies on long-term growth assumptions, so a safety margin is wise.
Common mistakes
- Treating optimistic return assumptions as guaranteed and leaving no margin of safety.
- Forgetting that you still must reliably cover current living costs every year.
- Never revisiting the plan if returns fall short of the assumptions.
FAQ
Is Coast FIRE the same as being able to retire?
No. It means your retirement is funded for the future, but you still need income to cover today's expenses until you actually retire.
Should I really stop contributing after reaching it?
You can, but many people keep saving something as a buffer against weak returns or higher future spending.