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 you've accumulated enough invested assets that — without ever contributing another dollar — compound growth alone will carry your portfolio to your full retirement number by your target retirement age.

Once you reach Coast FIRE, the financial pressure changes completely. You still need to cover your current living expenses, but you no longer need to save for retirement. Any income can go toward present-day enjoyment, lower stress, or simply covering bills. You've bought your future retirement with past savings, and compound interest handles the rest.

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, if you have $276,500 invested, you never need to save for retirement again. Left untouched at 7% for 25 years, it grows to $1,500,000 — your full retirement number.

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 dramatically the Coast FIRE number rises with age. At 22, you need under $75,000 — a realistic target within 3-5 years of aggressive saving. At 50, you need over $540,000.

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 her Coast FIRE number of $112,500 (targeting retirement at 65) in approximately 2.5 years — at age 30.5.

Her full FIRE number of $1,500,000 would take approximately 22 more years at the same rate.

The difference is stark: 2.5 years vs. 24.5 years of intensive saving to secure the same retirement outcome.

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, every percentage point of fees matters enormously because the money will compound for 30-40 years without additional contributions. A 0.5% fee difference on $200,000 costs approximately $375,000 over 35 years.

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

Use tax-advantaged accounts first

Growth in Roth IRA and 401k accounts is tax-deferred or tax-free. This effectively increases your real return by eliminating the tax drag that taxable accounts incur on dividends and capital gains.

Max your Roth IRA ($7,000/year in 2026) and 401k ($23,500/year in 2026) before investing in taxable accounts.

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? Yes — and it makes Coast FIRE easier. Subtract your expected annual pension/SS income from your retirement expenses before calculating your FIRE number. A $20,000/year pension reduces a $60,000 expense target to $40,000, lowering your FIRE number from $1.5M to $1M and your Coast FIRE number proportionally.

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? Yes — the math is universal. The specific tax-advantaged account types vary by country, but the underlying principle of saving enough early that compound growth handles retirement applies anywhere with accessible investment markets.