Coast FIRE: Stop Saving and Let Compounding Do the Work

What Is Coast FIRE?

Coast FIRE is the point where your invested portfolio is large enough that — without adding another dollar — compound growth alone will carry it to your full retirement number by a traditional retirement age. Once you hit your Coast FIRE number, you only need to earn enough to cover current living expenses. You can stop saving entirely.

This is different from traditional FIRE, where you accumulate enough to retire immediately. Coast FIRE is a milestone on the journey — a pressure release valve that lets you downshift careers, reduce hours, or take lower-paying work you actually enjoy, all while your investments grow in the background.

How to Calculate Your Coast FIRE Number

The Coast FIRE formula depends on three variables: your target retirement portfolio, your expected real (inflation-adjusted) return rate, and the number of years until your target retirement age.

Coast FIRE Number = Target Portfolio / (1 + Real Return Rate) ^ Years Until Retirement

For example, if you need $1,000,000 at age 65 and you are 35 years old, with a 7% real return: $1,000,000 / (1.07)^30 = $131,367. Invest $131,367 by age 35 and you never need to save another dollar for retirement. The Rule of 72 confirms this — at 7%, money doubles every 10.3 years. Over 30 years, that is roughly three doublings: $131,367 becomes $262,734, then $525,468, then approximately $1,050,936.

Coast FIRE Numbers by Age

The younger you are, the less you need to reach Coast FIRE. Here is what you need invested today to coast to $1,000,000 by age 65, assuming a 7% real return:

These numbers assume $1,000,000 as the target. If you are aiming for a Lean FIRE lifestyle at $30,000 per year (needing $750,000), multiply the coast numbers by 0.75. For Fat FIRE at $100,000 per year ($2,500,000), multiply by 2.5. Check our Lean FIRE vs [Fat FIRE guide](/blog/lean-fire-vs-fat-fire-explained) for more on choosing your target.

Why Dividend Investing Supercharges Coast FIRE

Traditional Coast FIRE assumes you leave your portfolio untouched and let price appreciation do the work. Dividend investing adds a second engine: reinvested dividends buy more shares, which generate more dividends, creating a compounding cycle on top of price growth.

A portfolio yielding 3% in dividends with 4% price appreciation delivers the same 7% total return, but the dividend component is more predictable and less volatile than relying on price growth alone. During the 'coast' period, DRIP (Dividend Reinvestment Plans) keeps your portfolio compounding even in flat or declining markets.

When you eventually reach full retirement, those same dividends become your income stream — no need to sell shares. Learn how reinvestment accelerates wealth building in our DRIP guide.

The Coast FIRE Lifestyle

Once you hit your Coast FIRE number, your relationship with work changes fundamentally. You no longer need a high salary — you just need to cover current expenses. This opens up options that traditional career advice ignores:

• Switch to a lower-stress job that pays less but offers better work-life balance.
• Go part-time and spend more time with family, on hobbies, or traveling.
• Start a passion project or small business without the pressure of it needing to replace your full income.
• Take a sabbatical — your retirement savings keep growing without you.
• Relocate to a lower cost-of-living area and work remotely.

Coast FIRE vs Other FIRE Strategies

Coast FIRE pairs naturally with Barista FIRE — once you have coasted, any part-time income covers expenses. The two strategies are often combined.

How to Get Started with Coast FIRE

1. Calculate your FIRE number using Annual Expenses / 0.04 (or use the Odalite FIRE Calculator for a personalized projection).
2. Determine your Coast FIRE number using the formula: FIRE Number / (1.07)^(Years to Retirement Age).
3. Compare your current portfolio to the Coast FIRE number — you may already be closer than you think.
4. If you have not hit your coast number yet, focus on maximizing savings rate now. Every dollar invested today has the longest compounding runway.
5. Once you reach your coast number, reassess your career. You now have permission to optimize for happiness, not salary.

For a structured approach to building your investment portfolio, read The Simple Path to Wealth by JL Collins — it aligns perfectly with the Coast FIRE philosophy of simple, long-term investing.

Risks and Limitations of Coast FIRE

• Market returns are not guaranteed — a prolonged downturn early in the coast period (sequence-of-returns risk) can delay your retirement date significantly.
• You still need to earn enough to cover living expenses — Coast FIRE does not eliminate the need for income, it eliminates the need for savings.
• Lifestyle inflation during the coast years can increase your FIRE number, moving the goalpost.
• Healthcare costs before Medicare eligibility (age 65 in the US) remain a major expense that must come from earned income.