Coast FIRE: When You've Saved Enough

Last updated: May 29, 2026
By Miguel Garcia

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.

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 to Calculate Your Coast FIRE Number

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.

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 Coast FIRE Matters 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. A 25-year-old maxing a Roth IRA and employer match could hit Coast FIRE by 35.

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.

Coast FIRE vs. Full Financial Independence

It's important to distinguish two milestones:

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 to Aim for Coast FIRE

Not everyone should target Coast FIRE. It depends on your situation:

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 to Reach Your Coast FIRE Number

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.

The Math Behind the Power

Why does Coast FIRE feel like a game-changer?

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.

Frequently Asked Questions