Coast FIRE Explained: When Your Savings Can Take Over

Last updated: September 2026 · Written by Hugo Cardozo

Coast FIRE isn't the same as retiring early

Coast FIRE means you've saved enough, early enough, that compound growth alone will carry your current retirement savings to your full retirement goal by your target age — even if you never contribute another dollar. You still work and still earn income, but you're no longer required to save for retirement; every future paycheck is free to go toward rent, travel, a career change, or anything else.

The two numbers that matter

Your projected balance is what your current savings grow to by your target retirement age, assuming an average annual return and no further contributions. Your coast number is the balance you'd need today for that same growth to reach your target by that age. If your current savings are at or above your coast number, you've reached Coast FIRE.

A worked example

Someone who is 30 with $50,000 saved, targeting a $1,250,000 nest egg by age 65, assuming a 7% average annual return: their $50,000 grows to about $533,800 by 65 with zero further contributions — well short of the $1,250,000 goal. Their coast number today is about $117,100, meaning they'd need to have saved that much already to coast the rest of the way. They still have a real gap to close before contributions can stop.

Why the assumed return matters so much

Small changes in the assumed annual return compound dramatically over 20-35 years. A more conservative return assumption (5-6%) gives a more cautious, achievable coast number; an aggressive one (9-10%) can make coasting look closer than it may realistically be. It's worth running the calculator at a couple of different return assumptions rather than trusting a single number.

What changes once you've coasted

Reaching Coast FIRE doesn't mean stopping work — it means your retirement savings rate becomes optional rather than required. Many people who hit their coast number choose to keep contributing anyway (to retire earlier or with more margin), while others use the freedom to take a lower-paying but more fulfilling job, since their retirement is already effectively funded by time and compounding.

Frequently asked questions

Is Coast FIRE the same as regular FIRE?

No. Regular FIRE (Financial Independence, Retire Early) means you have enough to fully retire now. Coast FIRE only means your current savings will grow into a full retirement by a target age with no further contributions — you're still expected to keep working and earning income until then.

Does Coast FIRE account for Social Security?

Not in the basic calculation — it typically projects your own savings only. Social Security, a pension, or other future income could mean your actual "number" needed from savings is lower than a pure Coast FIRE estimate suggests.

What if my target retirement age or nest egg goal changes later?

Your coast number changes too — a younger target age or a larger goal both raise the number you'd need today, while an older target age or smaller goal lower it. It's worth recalculating whenever a major life plan shifts.