Coast FIRE Calculator [Find Your Financial Freedom Number]

Coast FIRE Calculator

Find out if you have saved enough to stop investing and “coast” to retirement.

Please enter a valid age.
Must be greater than current age.
$
Enter a valid amount.
$
(In today’s dollars)
Enter a valid spending amount.
%
(Inflation-adjusted. Historically ~7% for S&P 500)
Enter a valid rate (1-20).
%
(The 4% rule is standard)
Enter a valid SWR (1-10).
Calculating…
Your Coast FIRE Number
$0
What you need saved TODAY
Ultimate Target FIRE Number
$0
What you need at age 65

Calculation Breakdown

Years to let investments grow: 0
Projected Portfolio at Retirement (If you stop investing now): $0
Amount short of Coast FIRE: $0

Coast FIRE Calculator: Find Your Financial Freedom Number

The traditional FIRE movement (Financial Independence, Retire Early) requires immense sacrifice. It demands extreme frugality and saving upwards of 50% to 70% of your income to quit your job in your 30s or 40s. But what if there was an easier, lower-stress way to achieve financial peace of mind without eating rice and beans for a decade?

Enter Coast FIRE.

Using our free Coast FIRE calculator, you can determine the exact dollar amount you need to save today so that you never have to invest another dime for traditional retirement.

Once you hit your Coast FIRE number, your money will grow in the background through compound interest, leaving you free to downshift your career, take lower-paying passion jobs, or simply spend 100% of your current paycheck without guilt.

What is Coast FIRE?

Coast FIRE is a financial milestone. You achieve Coast FIRE when you have saved enough money at an early age that, assuming average stock market returns, your portfolio will grow to your ultimate retirement target by your traditional retirement age.

Once you reach Coast FIRE, the heavy lifting of investing is over. You can just “coast.”

Because you no longer need to save for retirement, your cost of living plummets. You only need to earn enough money to cover your current living expenses. This opens the door to working part-time, becoming a freelancer, or taking a stress-free job that you actually enjoy.

Who is this calculator for?

  • Young Professionals: To figure out how front-loading investments in their 20s and 30s can buy them freedom later.
  • Burned-Out Employees: To see if they already have enough saved to step away from a toxic, high-stress career.
  • FIRE Enthusiasts: To track an important milestone on their journey to complete financial independence.

How to Use the Calculator

To get an accurate Coast FIRE calculation, input your personal financial data into the tool.

  1. Current Age: Your age today.
  2. Retirement Age: The age you actually plan to start withdrawing your money (traditionally 60 or 65).
  3. Current Invested Assets: The total balance of your 401(k), IRAs, and taxable brokerage accounts. Do not include your primary residence or car.
  4. Target Annual Spending: How much money you want to spend every year in retirement. Enter this in today’s dollars.
  5. Expected Annual Return: The rate at which you expect your investments to grow. Because we want to account for inflation, use an inflation-adjusted (real) return. Historically, the S&P 500 returns about 10% per year, minus 3% for inflation, making 7% a standard default.
  6. Safe Withdrawal Rate (SWR): The percentage of your portfolio you can safely withdraw each year in retirement without running out of money. The Trinity Study popularized the 4% Rule.

Understanding the Formula

Our calculator runs two separate mathematical formulas to give you your results.

1. Finding Your Target FIRE Number First, we must determine how much money you need to retire comfortably. We do this by dividing your annual retirement spending by your Safe Withdrawal Rate (SWR).

  • Formula: Target FIRE = Annual Spending / SWR
  • Example: $60,000 / 0.04 = $1,500,000

2. Finding Your Coast FIRE Number Next, we figure out how much you need today to reach that target using the reverse compound interest formula.

  • Formula: Coast FIRE = Target FIRE / (1 + Rate)^Years
  • Example: If a 30-year-old wants to retire at 65 (35 years of growth) with a 7% return, they divide $1.5M by (1.07)^35. Their Coast FIRE number is $140,466.

If that 30-year-old has $140,466 invested right now, they never need to save for retirement again!

Real-Life Coast FIRE Examples

Let’s look at how age impacts the magic of compound interest.

Scenario 1: The 25-Year-Old Software Engineer

Alex is 25 and wants $50,000/year in retirement at age 60. Using a 4% SWR, his target FIRE number is $1.25 Million. Because Alex has 35 years for his money to grow at 7%, his Coast FIRE number is incredibly low: $117,055. If Alex grinds for a few years and hits that number by 25, he can spend the rest of his life working low-stress jobs.

Scenario 2: The 40-Year-Old Teacher

Maria is 40 and wants $80,000/year in retirement at age 65. Her target FIRE number is $2 Million. Because Maria only has 25 years for compound interest to work, her Coast FIRE number is $368,498. If she has this amount in her 403(b), she can stop contributing and use her full paycheck to travel or pay down her mortgage.

Tips for Coast FIRE Success

  • Adjust for Inflation: Always use an inflation-adjusted return rate (like 6% or 7%) rather than a nominal rate (like 10%). This ensures your final target number maintains its purchasing power in the future.
  • Don’t Count Your House: Your primary residence is not a liquid, income-producing asset. Do not include your home equity in your “Current Invested Assets.”
  • Invest Aggressively: The Coast FIRE math assumes you are invested in broad-market index funds (like the S&P 500 or Total Stock Market). If your money is sitting in a savings account earning 3%, you will not hit your goals.

Common Mistakes

  • Lifestyle Creep: Coast FIRE relies on your “Target Annual Spending” remaining stable. If you hit Coast FIRE and suddenly decide you want a luxury boat in retirement, your original Coast number is no longer valid.
  • Ignoring Taxes: Remember that withdrawals from traditional 401(k)s and IRAs are taxed as income. If you want $60,000 of spending money, you may need to budget $70,000 to account for taxes.
  • Panic Selling: The stock market goes down. If you hit Coast FIRE and the market crashes 20%, do not panic. Compound interest recovers over decades. Stay the course.

FAQs About Coast FIRE Calculator

What is the difference between Coast FIRE and Barista FIRE?
Coast FIRE means you have saved enough for traditional retirement, so you stop investing and work just enough to cover your current living expenses. Barista FIRE is when you quit your high-stress career but take a part-time job specifically to get health insurance benefits while you let your portfolio grow.
Does Coast FIRE account for inflation?
Yes, as long as you use an inflation-adjusted (real) return rate. Historically, the stock market returns about 10% per year. By subtracting an average 3% for inflation, using a 7% return rate in the calculator ensures your results are calculated in today’s purchasing power.
Do I actually stop investing when I hit Coast FIRE?
You don’t have to! Many people hit Coast FIRE and continue investing anyway to reach complete financial independence even faster. Coast FIRE simply removes the *pressure* of needing to invest, giving you the mental freedom to take career risks or spend more on your present life.
What is the 4% rule?
The 4% rule, derived from the Trinity Study, is a rule of thumb for safe withdrawal rates. It suggests that if you have a balanced portfolio of stocks and bonds, you can withdraw 4% of its value in your first year of retirement, adjust for inflation each subsequent year, and practically never run out of money.
Why is my Coast FIRE number so low in my 20s?
Compound interest is heavily dependent on time. If you are in your 20s, your money has 35 to 40 years to double multiple times before traditional retirement. A single dollar invested at age 25 is vastly more powerful than a dollar invested at age 45.
What if the stock market crashes after I hit Coast FIRE?
Coast FIRE relies on long-term historical averages. While the market will experience crashes, over a 20 or 30-year horizon, it has historically averaged an upward trajectory. However, if a crash makes you nervous, you can always continue contributing a small amount to act as a financial buffer.
Can I use Coast FIRE to retire at 40?
No. Coast FIRE is designed to let your portfolio grow until a *traditional* retirement age (like 60 or 65). If you want to actually retire and completely stop working at age 40, you need to reach your full Target FIRE number, not just your Coast FIRE number.
Should I include my 401(k) company match in Coast FIRE planning?
If you plan to completely “coast” and stop contributing to your 401(k), you will likely lose your employer match. The math for Coast FIRE assumes zero future contributions from you OR your employer. If you choose to keep contributing just to get the match, you will reach your goals even faster!
Does Coast FIRE include Social Security?
Most FIRE calculators, including this one, do not automatically factor in Social Security, acting as a conservative buffer. If you expect Social Security to cover $20,000 of your expenses, you can simply lower your “Target Annual Spending” input by $20,000 to see your adjusted Coast number.
Can I still do Coast FIRE if I have debt?
It depends on the debt. Low-interest debt like a mortgage is generally fine. However, high-interest consumer debt (like credit cards with 20% APRs) destroys wealth faster than the stock market builds it. You should pay off high-interest debt before attempting to reach Coast FIRE.

Conclusion

Reaching financial independence doesn’t mean you have to grind at a miserable job until your hair turns gray. Coast FIRE offers a brilliant middle ground. By aggressively investing early in your career and letting compound interest do the heavy lifting, you can buy back your time and freedom decades before traditional retirement age.

Use this Coast FIRE calculator regularly to track your progress. Once you hit that magic number, you can take a deep breath, downshift your career, and finally start designing a life you don’t need a vacation from.