Coast FIRE: The Plan Where You Stop Saving and Still Retire on Time

Sarah is 32. She has $197,000 in her 401(k) and Roth IRA, invested mostly in a total stock market index fund. She plans to spend $60,000 per year in retirement. And she's thinking about something that sounds almost reckless: stopping her retirement contributions entirely.

Not because she's giving up. Because she's done the math. If her portfolio earns a 7% inflation-adjusted return for the next 30 years, that $197,000 grows to roughly $1.5 million by the time she's 62. Enough to withdraw $60,000 a year under the 4% rule. Without adding another dollar.

This is Coast FIRE. And it might be the most psychologically liberating milestone on the path to financial independence.

The short version: Coast FIRE is the point where you've invested enough that, with zero additional contributions, compound growth alone will build your portfolio to a full retirement by a traditional age (usually 60 to 65). After hitting it, you only need to earn enough to cover today's bills.

How Coast FIRE Works

The concept is straightforward. You front-load your retirement savings aggressively in your 20s and 30s, then let compound interest do the remaining work over two or three decades. Once you've hit your "coast number," you don't need to save for retirement anymore. You just need to pay your current bills.

This changes your relationship with work in a fundamental way. You don't need the $120,000 corporate salary anymore. You could teach yoga, work at a bookstore, freelance 20 hours a week, or take a nonprofit job that pays $38,000. Your future is already funded. Your present just needs to break even.

It's different from full FIRE, where you stop working entirely. And it's different from Barista FIRE, where you supplement investment withdrawals with part-time income. With Coast FIRE, you're not touching your investments at all. You're just letting them cook.

For a full overview of all FIRE variants and how they compare, see our complete guide to FIRE.

The Math: Calculating Your Coast Number

The formula works backward from your retirement target.

Step 1: Calculate your full retirement number using the 25× rule. Step 2: Discount that number to today's value, using your expected real return and the number of years until your target retirement age.

Coast Number = Retirement Target ÷ (1 + Real Return)^Years

Let's walk through three scenarios, all assuming $60,000 in annual retirement spending, a $1.5 million target, and 7% real returns:

The difference between starting at 25 and starting at 35 is $134,000. Time is doing the heavy lifting here, not money.

At age 30, if you have $197,000 invested, you could theoretically stop all retirement contributions and still end up with $1.5 million at 60. That same $1.5 million would require saving roughly $1,200 per month for 30 years if you started from zero [1].

Front-loading saved Sarah (from our opening example) the equivalent of $432,000 in future contributions. That's the power of compounding, and it's why Coast FIRE targets the 25-to-35 age window so aggressively.

Where Most People Actually Stand

Here's the tension. The average Millennial 401(k) balance is about $67,300 [2]. The median for all families is closer to $87,000 [3]. Both numbers fall well short of typical coast targets.

The average participant deferral rate in employer plans is 7.7%, or 12.3% including employer match [4]. Coast FIRE often demands a savings rate of 40% to 50% during the front-loading phase, sometimes for five to ten years. That's roughly four times the national average.

This doesn't mean it's impossible. It does mean it requires intentional, often uncomfortable, trade-offs: roommates in your 20s, used cars, minimal dining out, aggressive salary negotiation. The upside is that those sacrifices are concentrated into a short window. Once you hit your coast number, the pressure valve opens.

Most people who talk about Coast FIRE online didn't realize they'd reached it until they ran the numbers retrospectively. That "wait, am I already there?" moment is one of the genuinely delightful surprises in personal finance. But planning for it deliberately, and knowing when you've crossed the line, is better.

Coast FIRE vs. Other FIRE Variants

Coast FIRE is the most moderate flavor. You're not betting on a 50-year retirement starting at 35. You're not depending on the market to sustain withdrawals for decades. You're just trusting that a broadly diversified portfolio will grow at something close to its historical average over 25 to 35 years.

That trust isn't blind. The S&P 500 has returned roughly 10.6% nominally (about 6.8% after inflation) since 1957 [5]. There is no 30-year period in U.S. history where a diversified stock portfolio lost money. But past performance doesn't guarantee future results. You already knew that. It's still worth saying out loud.

The Real Risks

Coast FIRE is built on assumptions. And assumptions break.

Market returns aren't guaranteed. Using 7% real returns is reasonable based on history. But a prolonged period of lower returns (Japan's stock market was flat for nearly 30 years starting in 1989) would leave your portfolio short. If you get 5% instead of 7%, a $197,000 coast number at age 30 grows to $852,000 by 60, not $1.5 million. That's a 43% shortfall.

Inflation might run hotter than expected. The current rate is 2.7% [6]. But the 2022-2023 spike reminded everyone that inflation isn't always tame. Higher inflation erodes real returns and increases the spending number you're targeting.

You might stop contributing and never restart. This is the psychological trap. Once you've told yourself "I don't need to save anymore," returning to a high savings rate during a market drawdown is emotionally difficult, even if it would be financially wise.

Life changes. Kids, health events, divorce, a career change that cuts income. The "just cover expenses" part of Coast FIRE sounds simple until expenses jump 40% because of a child or a cross-country move.

The best Coast FIRE plans acknowledge these risks with a buffer. Save 10% to 20% beyond your coast number. Keep contributing at a modest rate (even 5% or 10%) after you "coast." Treat the number as a minimum, not a permission slip to spend everything you earn.

Who Coast FIRE Is Actually For

Coast FIRE works best for people who don't hate work. They just hate the pressure.

If your goal is to never work another day, full FIRE or Fat FIRE is the better target. If your goal is to escape a demanding, high-stress career and downshift to something meaningful but lower-paying, Coast FIRE gives you the math to do it without sacrificing your future.

It's also powerful for people in their late 20s or early 30s who've been aggressive savers and suddenly wonder: "Wait, do I already have enough for compound interest to handle the rest?" Often the answer is closer to yes than they think.

And it's a genuinely useful concept for people who prioritize building a cash safety net and paying for current life goals (a house, a wedding, starting a business) without guilt about their retirement accounts. Once you've hit your coast number, redirecting income toward nearer-term goals is financially sound, not irresponsible.

Your Next Move

1. Calculate your retirement target. Use the 25× rule on your expected annual retirement spending. Use our FIRE calculator to run different scenarios.
2. Run the coast number. Divide your retirement target by (1.07)^years until your target retirement age. If your current invested balance exceeds that number, congratulations. You've reached Coast FIRE.
3. If you're not there yet, calculate the gap. Subtract your current investments from your coast number. Divide by the number of months until your target coast age. That's your required monthly contribution.
4. Don't stop cold. Even after hitting your coast number, consider contributing at least enough to capture your full employer 401(k) match. Free money is free money.
5. Revisit annually. Markets move. Spending changes. Recalculate your coast number once a year to make sure compound interest is still on track.

References

1. OfficialData.org. (2026). "S&P 500 Historical Return Calculator." OfficialData.org.
2. Fidelity Investments. (2025). "Average Retirement Savings by Age." Fidelity.com. https://www.fidelity.com/learning-center/personal-finance/average-retirement-savings
3. Federal Reserve. (2023). "Survey of Consumer Finances." FederalReserve.gov. https://www.federalreserve.gov/econres/scfindex.htm
4. Vanguard. (2025). How America Saves 2025. Vanguard.com. https://institutional.vanguard.com
5. OfficialData.org. (2026). "S&P 500 Historical Annual Returns." OfficialData.org.
6. Bureau of Labor Statistics. (2026). "Consumer Price Index Summary." BLS.gov. https://www.bls.gov/cpi/