Have you already won? Coast FIRE means you have enough invested today that compound interest alone will reach your retirement number — without adding another cent.
Coast FIRE is the point where you have saved enough that, even if you never invest another dollar, compound growth alone will grow your portfolio to your full FIRE number by traditional retirement age (typically 65). After reaching Coast FIRE, you only need to earn enough to cover your current living expenses — you can stop saving entirely.
This makes Coast FIRE appealing for people who want to downshift to lower-paying but more meaningful work, take time off for travel or family, or simply reduce financial stress without fully retiring. You have already done the hard work of saving — now time and compound returns do the rest.
The math: if your FIRE number at 65 is $1,500,000 and you expect 7% annual returns, your Coast FIRE number at age 35 is roughly $387,000. Save that by 35, and you are mathematically set for retirement at 65 without saving another cent.