What Is Your Coast FIRE for Retirement?

Coast FIRE is a financial independence strategy where you save and invest enough early in life to eventually stop contributing to retirement accounts, letting compound growth handle the rest. Once you’ve reached your “coast” number, you can shift to lower-paying or more flexible work. Unlike traditional FIRE, Financial Independence, Retire Early, Coast FIRE doesn’t require early retirement—it simply gives you the option later.

Work with a financial advisor to build a retirement plan that fits your goals, lifestyle and timeline.

What Is Coast FIRE?

Coast FIRE hinges on the idea that time, rather than continued saving, will carry your retirement portfolio to maturity. The approach relies on reaching a specific savings milestone early, typically by your 30s or 40s, after which additional retirement contributions are no longer necessary.

From there, you leave the portfolio untouched to grow through compounding until a traditional retirement age. This separates financial independence from early retirement, offering the freedom to shift into lower-stress or more personally meaningful work while relying on passive portfolio growth for the long term.

Coast FIRE vs. Regular FIRE

The core difference between Coast FIRE and regular FIRE lies in the timeline and purpose of saving. Regular FIRE requires building a portfolio large enough to fully fund retirement. This often allows for a complete exit from the workforce well before traditional retirement age. That approach demands aggressive saving, high income and often significant lifestyle changes to accelerate the path to early retirement.

Coast FIRE, on the other hand, targets a more moderate milestone—enough saved early so that the portfolio can compound without further contributions. Rather than retiring early, someone pursuing Coast FIRE continues working, but only to cover present-day expenses. This makes Coast FIRE more accessible to people who want financial security without the pressure to exit the workforce prematurely.

It also reduces the long-term risks tied to drawing down a portfolio over several decades, since you won’t begin making withdrawals until a more traditional retirement age.

Calculating Your Coast FIRE Number

You’ll need to calculate how much you need to save to hit your Coast FIRE goals. There is no single amount that will work for everyone. Your total amount will depend on the factors in the calculation below and also include your age, lifestyle and your individual needs in retirement.

Start with the amount you’ll need at retirement. This is your target nest egg. It is often estimated using the 25x rule derived from the 4% rule, which multiplies expected annual retirement expenses by 25. Then, work backward to determine how much you need invested today for that amount to grow—without additional contributions—by your desired retirement age, assuming a reasonable annual return.

To calculate your Coast FIRE number, you need to understand your portfolio’s growth rate and how much you plan to withdraw.

Rate of Growth

In the absence of infallible projections of how an investment portfolio, savings account or combination of both will grow, adherents must estimate the rate at which their nest egg will increase. That will determine how long until one’s money reaches an amount that allows retirement. Taking inflation into account, common estimates of the long-term growth rate of a nest egg range from 5% to 7%.

Rate of Withdrawal

You also need to estimate how much you can safely withdraw in retirement. A 4% withdrawal rate is often mentioned as a reasonable target. This is based on a 1998 study by three finance professors at Trinity University. Under the 4% rule created by William Bengen, you withdraw 4% from a 50/50 mix of equities and bonds in your first year. Future withdrawals are adjusted for inflation. Doing so, the rule states, extends the life of your portfolio to 30 years.

However, a static withdrawal rate like the 4% rule may not meet every retiree’s income needs, especially if their expenses vary from year to year. A more dynamic withdrawal strategy may be necessary.

Coast FIRE Example

To find your Coast FIRE number, calculate how much you’d need to invest today for that amount to grow on its own by the time you reach retirement age. Suppose you expect to spend $100,000 per year in retirement and want that income to last indefinitely. Using the 25x rule, you’d need a retirement portfolio of $2.5 million ($100,000 × 25).

You can then plug those numbers into this formula:

Coast FIRE number = Target Retirement Portfolio/(1+R)ⁿ

In the formula above, “R” represents the expected annual rate of return, expressed as a decimal. Meanwhile, “n” is the number of years until retirement.

Using the formula, you would need approximately $334,000 invested today to hit your $2.5 million savings goal in 35 years.

How does your retirement savings stack up for your long-term plans? Try this calculator to see how your retirement is shaping up:

Bottom Line

Coast FIRE offers a way to front-load your retirement savings while keeping the option to work for current income. It shifts the focus from aggressively chasing early retirement to building long-term financial confidence through time and growth. With the right assumptions and a clear savings goal, it creates space for more flexibility in how you approach your career, your spending, and your path to retirement.

Tips on Saving for Retirement

• Working with a financial advisor can help you avoid missteps and miscalculations as you prepare for retirement. Finding a financial advisor doesn’t have to be hard. SmartAsset’s free tool matches you with vetted financial advisors who serve your area, and you can have a free introductory call with your advisor matches to decide which one you feel is right for you. If you’re ready to find an advisor who can help you achieve your financial goals, get started now.
• Calculating how much you’ll need to retire without worry is an important step in securing that goal. If you want to find ways to build up your savings, consider participating in an employer-sponsored 401(k) matching program.

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