Use this coast fire calculator to find the amount you need invested today so your portfolio can grow to your retirement goal without any more contributions. Enter your current age, retirement age, current investments, FIRE number, and expected return to see whether you can already coast.
Coast FIRE is useful because it turns a vague retirement goal into a clear checkpoint. If you are already there, you may have more room to reduce hours, change careers, or focus new savings on shorter-term goals. If you are not there yet, the gap gives you a concrete target.
Include 401k, IRA, brokerage — anything invested for retirement.
Not sure? Use your annual expenses x 25. Example: $40,000/year x 25 = $1,000,000.
7% is a common estimate for a diversified index fund portfolio after inflation.
What Is Coast FIRE?
Coast FIRE means you have enough invested that compound growth can carry you to your full retirement number by your target retirement age. You still need income for today’s bills, but you no longer need to keep adding money to the retirement portfolio for the math to work.
That makes Coast FIRE different from full FIRE. Full FIRE means your portfolio can support your lifestyle immediately. Coast FIRE means your future retirement is already on track if you leave the money invested and avoid raiding it early. Many people use it as a midpoint between aggressive saving and full financial independence.
The milestone can change the way you think about work. Someone who hits Coast FIRE might keep their job but stop chasing every raise, switch to a lower-stress role, take a sabbatical, or use future savings for a home, business, travel, or family goal. The calculator above shows whether your current investments are large enough to make that possible.
How the Coast FIRE Calculator Works
The calculator works backward from your target retirement number. It discounts your future FIRE number by the number of years your investments have left to compound. The formula is: Coast FIRE number = FIRE number / (1 + expected return) ^ years until retirement.
Current age and target retirement age determine how much compounding time you have. More years lowers the amount you need today. Fewer years raises it. That is why Coast FIRE tends to be much easier to reach for people who start investing early.
Current savings and investments should include retirement accounts and taxable brokerage money that is invested for long-term growth. Do not include emergency cash, checking account balances, or money you plan to spend soon. Those dollars are important, but they are not compounding toward retirement.
Your FIRE number is the portfolio value you want by retirement. A quick estimate is annual retirement spending multiplied by 25. For example, $40,000 of annual spending points to a $1,000,000 FIRE number. For a more complete retirement target, compare this page with the FIRE calculator.
Coast FIRE Example
Suppose you are 30, want to retire at 65, expect a 7% annual return, and want $1,000,000 invested by retirement. With 35 years to compound, the Coast FIRE number is about $93,700. If you already have that amount invested, it could grow to roughly $1,000,000 by age 65 without additional contributions.
Change the return rate and the answer moves quickly. At a lower return, you need more invested today. At a higher return, you need less. That is why it is smart to run several scenarios instead of treating one calculator output as a promise.
What Return Rate Should I Use?
A 7% default is a common long-term planning assumption for a diversified stock-heavy portfolio after inflation. Conservative planners may prefer 5% or 6%, especially if they expect to hold more bonds as retirement gets closer. Aggressive investors may test 8% or 9%, but higher assumptions can make the plan look easier than it really is. For a neutral check on compounding math, compare your assumptions with the Investor.gov compound interest calculator.
The safest approach is to run a range. Use 5% for a cautious case, 7% for a middle case, and 9% for an optimistic case. If your plan only works at the optimistic rate, you may want to keep contributing longer before calling yourself Coast FIRE. FINRA also explains why asset allocation and diversification matter when you are managing investment risk.
If you want to see how any starting balance grows over time, use the Compounding Calculator. If you are still building the portfolio month by month, the DCA calculator can show how recurring investments add up.
How Coast FIRE Fits With Other Retirement Paths
Coast FIRE sits between traditional retirement planning and early retirement. It does not mean you can stop working today. It means the retirement bucket is far enough ahead that future investment growth may finish the job. That can be a powerful goal for people who want more flexibility before full retirement.
Barista FIRE is closely related. With Barista FIRE, you may work part time or in a lower-stress job to cover current expenses while your investments compound. Coast FIRE tells you whether the long-term retirement side of that plan is mathematically on track.
Traditional retirement planning still matters too. Taxes, healthcare, Social Security, sequence risk, and market downturns can all affect the real outcome. The standard retirement guide gives useful context if you are comparing a conventional path with a FIRE-style path.
Common Coast FIRE Mistakes
Using nominal returns with today-dollar spending is one of the biggest mistakes. If your retirement spending target is in today dollars, use an inflation-adjusted return assumption. Mixing nominal growth with current expenses can make your Coast FIRE number look too low.
Counting money that is not invested is another problem. Cash savings, home equity, and money earmarked for a near-term purchase may be part of your net worth, but they should not be counted as Coast FIRE assets unless they are actually invested for retirement.
Ignoring portfolio risk can also lead to bad decisions. Coast FIRE is a projection, not a guarantee. Market returns can arrive in rough sequences. Before reducing contributions, read about sequence of returns risk and consider adding a margin of safety.
Frequently Asked Questions
A coast fire calculator estimates how much you need invested today for that money to grow into your retirement target by your chosen retirement age, assuming no more contributions.
Regular FIRE means your portfolio can fund your lifestyle now. Coast FIRE means your portfolio can grow into your future retirement number by your target retirement age if you leave it invested.
You may be able to stop investing for retirement, but it is usually smart to keep a margin of safety. Returns are uncertain, life changes, and future expenses may be higher than expected.
Usually no. A primary home can be valuable, but it does not compound like a retirement portfolio unless you plan to sell it, downsize, or use the equity as part of your retirement plan.
It is a reasonable long-term estimate for a stock-heavy portfolio after inflation, but it is not guaranteed. Run lower-return scenarios too so your plan is not dependent on an optimistic market.
Ready to Use Your Coast FIRE Number?
Run the calculator with your real numbers, then run it again with conservative assumptions. If you are already over the line, your next decision is not just financial. It is about how much freedom you want now versus how much extra safety you want later.
If you are below the line, the gap is still useful. It tells you exactly what you are trying to close. Keep investing consistently, review your spending target once or twice a year, and let time do as much work as possible.
Some investors add higher-growth assets for a small part of the portfolio, but volatility cuts both ways. If you trade crypto or other volatile assets, keep position size under control. Bitunix lets users sign up and trade without KYC, but it should not replace a diversified long-term plan.