Coast FIRE: The Strategy That Lets You Stop Saving for Retirement

What is Coast FIRE?

Coast FIRE is a milestone within the broader FIRE movement where your current invested assets are projected to grow to your full retirement target by your target retirement age without further contributions, based on an assumed return.

Once you reach a Coast FIRE estimate, the financial pressure may change. You still need to cover current living expenses, and the projection should be reviewed as returns, fees, inflation, spending, and your retirement date change. If the assumptions continue to hold, additional retirement contributions may no longer be required to reach the modeled target.

The term "coasting" is apt: after years of aggressive saving and investing, you shift out of high gear and let momentum carry you forward.

How to calculate your Coast FIRE number

Your Coast FIRE number is your full FIRE number mathematically discounted back to today's dollars, accounting for the compound growth that will occur between now and retirement.

The formula:

Coast FIRE Number = Full FIRE Number ÷ (1 + annual return)^years to retirement

Step-by-step example:

1. Determine annual retirement expenses: $60,000/year
2. Calculate full FIRE number: $60,000 × 25 = $1,500,000
3. Inputs: Current age 35, target retirement age 60, expected return 7%
4. Years to retirement: 60 - 35 = 25 years
5. Coast FIRE calculation: $1,500,000 ÷ (1.07)²⁵ = $1,500,000 ÷ 5.427 = $276,500

At age 35, $276,500 left invested for 25 years would grow to approximately $1,500,000 at a steady 7% annual return. This is an illustrative projection, not a guaranteed outcome.

Coast FIRE numbers by age (complete table)

Using $60,000 annual retirement expenses ($1,500,000 FIRE number) and a 7% expected return, targeting retirement at 65:

Notice how the modeled Coast FIRE number rises as the time available for compounding falls. In this example it is about $81,800 at age 22 and $543,600 at age 50. Whether either amount is practical depends on income, expenses, existing savings, taxes, and actual returns.

Every year you delay starting is another year of compounding you lose — and the required Coast FIRE number jumps significantly.

For different retirement ages, use our Coast FIRE calculator to find your personal number instantly.

Why Coast FIRE is achievable much earlier than full FIRE

Full FIRE typically requires 15-25 years of aggressive saving to accumulate $1M-2M+. Coast FIRE often requires only 5-10 years to reach a much smaller number.

Example: Jennifer, age 28, earns $75,000/year and saves aggressively: - Saves $2,500/month - Current savings: $15,000 - Expected return: 7%

At this pace, Jennifer reaches a $112,500 interim target in approximately 35 months under monthly compounding with end-of-month contributions.

Her full FIRE number of $1,500,000 would take approximately 21 years in total at the same modeled rate and contribution amount.

The comparison illustrates how an interim Coast FIRE milestone can arrive much earlier than the full target. Neither timeline secures a retirement outcome because returns and future spending are uncertain.

What changes at Coast FIRE

Reaching Coast FIRE is a fundamental shift in your relationship with money and work.

Before Coast FIRE: You need to save aggressively. Your income must cover both current expenses AND retirement contributions. High-income jobs become necessary. Career decisions are constrained by salary requirements.

After Coast FIRE: You only need to cover current expenses. A lower-paying job you love becomes viable. Part-time work becomes sufficient. Career sabbaticals are possible. Geographic flexibility increases — you can move to a lower cost-of-living area without jeopardizing retirement.

Many people find Coast FIRE more achievable as a first goal than full FIRE, and reaching it creates a virtuous cycle: less financial stress leads to better life decisions, which often leads to continued wealth accumulation even without forced saving.

Coast FIRE vs other FIRE variants

The FIRE movement has spawned several sub-strategies, each with different targets and timelines:

Coast FIRE is unique in that it doesn't require you to actually retire — just to eliminate the retirement saving obligation from your income requirements.

The Flamingo FIRE strategy: Coast FIRE's practical cousin

Flamingo FIRE combines Coast FIRE with Barista FIRE: save aggressively to reach Coast FIRE, then shift to part-time or flexible work that covers current expenses.

The result: no retirement savings pressure, lower work requirements, and a full retirement portfolio waiting at the end without ever contributing again.

Example: Marcus reaches Coast FIRE at 33 with $165,000 invested (targeting retirement at 65 on $55,000/year). He leaves his stressful $120,000/year corporate job and takes a $45,000/year remote consulting role that covers his living expenses. His $165,000 grows untouched to $1,375,000 by age 65.

He "worked" for 32 more years but with dramatically lower stress, more flexibility, and far greater life satisfaction — all while securing a full retirement.

How to accelerate reaching Coast FIRE

Increase your savings rate in the early years

The Coast FIRE number is smallest when you're young. If you can save aggressively for 3-7 years in your 20s, you can potentially reach Coast FIRE before 30 — securing decades of financial freedom ahead.

Even $500-1,000/month invested consistently in your early 20s can reach Coast FIRE by age 28-32 for most spending levels.

Minimize fees and maximize returns

At the Coast FIRE stage, fees matter because they reduce the return available for compounding. On a $200,000 starting balance over 35 years, the modeled difference between a 7% annual return and a 6.5% net return is approximately $323,000.

Use total market index funds with expense ratios under 0.10%.

Use tax-advantaged accounts first

U.S. Roth IRAs can provide tax-free qualified distributions, while traditional 401(k) accounts generally defer tax until withdrawal. Eligibility, plan terms, fees, and future tax treatment all affect the comparison with a taxable account.

For 2026, the U.S. IRA contribution limit is $7,500 and the employee 401(k) deferral limit is $24,500, subject to eligibility and catch-up rules. See the IRS 2026 retirement-plan limits. Account order should reflect your plan match, fees, taxes, liquidity needs, and jurisdiction.

Don't touch it after you reach Coast FIRE

The entire Coast FIRE strategy depends on leaving the invested amount untouched. Any withdrawals restart the compounding clock and may push you below your Coast FIRE number.

Build a separate emergency fund (6-12 months of expenses in cash) before reaching Coast FIRE so you never need to touch your investment portfolio.

Coast FIRE calculation: different return rate assumptions

Return rate assumptions significantly affect your Coast FIRE number. Here's the sensitivity for a 35-year-old targeting retirement at 65 with a $1,500,000 FIRE number:

A conservative 5% assumption nearly doubles the required amount compared to 7%. Most financial planners use 6-7% for long-term real return projections with a diversified equity portfolio.

What if markets don't cooperate?

Coast FIRE depends on future returns meeting your assumptions. This is the primary risk: if markets return 4% instead of 7% over your coasting period, your portfolio won't reach the full FIRE number.

Mitigation strategies:

1. Use a conservative return assumption. Plan on 6% rather than 8% to build in a margin of safety.

2. Continue small contributions if your income allows. Coast FIRE means you don't have to contribute — not that you shouldn't if you can.

3. Remain willing to work slightly longer if needed. If at age 60 your portfolio is at 85% of your FIRE number due to poor returns, a few extra years of work or part-time income bridges the gap.

4. Keep your Coast FIRE number updated. Recalculate annually as your spending expectations, return assumptions, and timeline evolve.

Frequently asked questions

Is Coast FIRE the same as "set it and forget it" retirement? Not exactly. You still need to monitor your investments, rebalance periodically, and ensure you're on track. But you no longer need to actively contribute, which eliminates the primary financial pressure most working adults feel.

What happens to Coast FIRE if I change my retirement spending target? It scales directly. If you decide you want to spend $80,000/year instead of $60,000/year in retirement, your full FIRE number rises from $1.5M to $2M, and your Coast FIRE number rises proportionally. Recalculate any time your target changes.

Can I use Coast FIRE if I have a pension or Social Security? Potentially. Model pension or U.S. Social Security income only from the age when it is expected to begin, and fund the years before that date separately. Benefit amounts, eligibility, taxes, and claiming ages vary, so use a personal estimate rather than subtracting delayed income from every retirement year.

What if I reach Coast FIRE but then have a major life expense? If you need to withdraw from your Coast FIRE portfolio for a major expense, you may fall below your Coast FIRE number and need to resume saving until you rebuild it. This is why maintaining a separate emergency fund and not conflating Coast FIRE savings with accessible savings is critical.

At what age is Coast FIRE most impactful? The younger you reach Coast FIRE, the more powerful it is. Coast FIRE at 25 means 40 years of compounding without contributions — the math is extraordinary. Coast FIRE at 50 still leaves 15 years of compounding but requires a much larger initial amount. The optimal strategy is to reach Coast FIRE as early as possible, even if it means a lower spending target in retirement.

Does Coast FIRE work outside the US? The compound-growth formula is not country-specific, but taxes, account rules, inflation, investment access, fees, pensions, healthcare, and retirement systems vary by jurisdiction. Adapt the assumptions to the country where you save and expect to retire.