Coast FIRE: When You've Saved Enough

Last updated: May 29, 2026
By ITINWorks Team

What Is Coast FIRE?

Coast FIRE is a milestone on the way to retirement where you've saved enough that compound growth alone will carry you to your retirement number. For example, $117,000 invested at age 30 grows to $1.25 million by 65 at 7% returns — without another dollar contributed. You still work, but only to fund your lifestyle, not your retirement.

Once you hit Coast FIRE:

• You stop contributing to retirement accounts
• Your invested money grows on its own schedule
• You only need to earn enough for living expenses
• Psychologically, the pressure is off — you've already won

You're not fully retired. You still work. But you're no longer saving for retirement — you're just funding your lifestyle.

How Do I Calculate My Coast FIRE Number?

Divide your FI number (annual retirement spending × 25) by your expected return rate compounded over the years until retirement. At a typical 7% return and a retirement age of 65, a 30-year-old targeting $50,000 of annual spending needs $1,250,000 ÷ 1.07³⁵ ≈ $117,000 invested today.

Formula: Coast FIRE Number = FI Number ÷ (1 + Return Rate)^{Years Until Retirement}

Breaking this down:

• FI Number: Your retirement target (multiply annual spending by 25)
• Return Rate: Expected investment return (7% is typical for stock-heavy portfolios)
• Years Until Retirement: Your age now vs. target retirement age (usually 65)

Example: Calculating Your Coast FIRE Number

You're 30 years old, expect to spend $50,000/year in retirement, and want to retire at 65.

Step 1: Calculate FI Number = $50,000 × 25 = $1,250,000

Step 2: Apply the formula:

Coast FIRE Number = $1,250,000 ÷ (1.07)^{35 years}
Coast FIRE Number = $1,250,000 ÷ 10.68
Coast FIRE Number = $117,000

Interpretation: If you have $117,000 invested today at age 30, compound growth at 7% will grow it to $1.25 million by age 65. You're done saving. You just need to earn your living expenses.

What Are the Coast FIRE Numbers by Age?

Here's a reference table assuming $60,000/year retirement spending ($1.5M FI number), 7% real annual returns, retiring at 65:

Notice the pattern: Each 5-year delay requires approximately 40% more invested upfront. Starting early is exponentially more powerful.

Why Does Coast FIRE Matter for ITIN Holders?

You Can Hit It Earlier Than Traditional Retirement Savers

Many ITIN holders start their careers in lower tax brackets and can aggressively save in their 20s and 30s — and a 25-year-old maxing a Roth IRA ($7,500 per year) plus an employer match could hit Coast FIRE by 35. Once that happens, career flexibility opens up: start a business, reduce hours, or take a less stressful job.

Once that happens, career flexibility opens up: start a business, reduce hours, take a less stressful job. You've already won the retirement game.

Psychological Freedom

Coast FIRE isn't about retiring early. It's about proving to yourself that time + discipline = a reliable retirement path.

Knowing you've already hit Coast FIRE changes how you think about money. No more panic. No more wondering "will I have enough?" The math says yes.

How Does Coast FIRE Compare to Full Financial Independence?

Coast FIRE is the checkpoint; full financial independence (FI) is the finish line. At Coast FIRE you've saved enough that compound growth finishes the job while you work for living expenses. At full FI, your portfolio covers all expenses through the 4% safe withdrawal rule and work becomes optional. The two milestones differ as follows:

Coast FIRE: You've saved enough. Compound growth finishes the job. You still work for living expenses.

Full Financial Independence (FI): Your invested portfolio generates enough income to cover all expenses (via the 4% safe withdrawal rule). You don't have to work.

Coast FIRE is the checkpoint. FI is the finish line.

When Should I Aim for Coast FIRE?

Coast FIRE makes the most sense if you have several decades until retirement (roughly ages 25–45), value career flexibility, and are building wealth incrementally. Full FI fits better if you can save aggressively — 30%+ of income — and want to stop working in 10–15 years instead of 30. Here is the breakdown:

Coast FIRE makes sense if you:

• Have several decades until retirement (age 25–45)
• Want psychological certainty about retirement
• Value career flexibility over maximum early retirement
• Are building wealth incrementally, not aggressively

Full FI might make more sense if you:

• Can save aggressively (30%+ of income)
• Want to stop working in 10–15 years, not 30
• Have a high-income period that won't last forever

How Do I Reach My Coast FIRE Number?

Reaching Coast FIRE takes 5 steps: calculate your number with the formula above, estimate your annual savings capacity, fill tax-advantaged accounts first (Roth IRA, then 401(k)), invest in broad index funds like FZROX and FZILX, and review annually until your balance crosses the target — then stop contributing.

Step 1: Calculate your Coast FIRE number using the formula above.

Step 2: Estimate how much you can save per year (after taxes and living expenses).

Step 3: Invest in a Roth IRA or employer 401(k) first, then a taxable brokerage for extra capacity.

Step 4: Use broad index funds (like FZROX for total US stock, FZILX for international) — they have the lowest fees and historically the most reliable returns.

Step 5: Review annually. When your invested balance reaches your Coast FIRE number, stop contributing and let compound growth take over.

What Is the Math Behind Coast FIRE's Power?

Compound growth is exponential, not linear — money grows 7% on an increasingly large base. A 25-year-old who hits Coast FIRE with $100,000 invested watches it reach $140,000 by 30, $275,000 by 40, $538,000 by 50, and $1.5 million by 65 without contributing another dollar.

Compound growth is exponential, not linear. Your money doesn't grow 7% every year — it grows 7% on an increasingly large base:

Age 25, just hit Coast FIRE with $100,000 invested at 7% annual return:

• Age 30: $140,000 (grew $40,000 without you)
• Age 40: $275,000 (grew $175,000 without you)
• Age 50: $538,000 (grew $438,000 without you)
• Age 65: $1,500,000 (grew $1,400,000 without you)

That's the power of compounding. You did the hard work early. Time does the rest.

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