What is Coast FIRE? How to Know If You've Already Won

Most people think of FIRE as an all-or-nothing milestone — you either have enough to retire or you don't. Coast FIRE introduces a middle ground: a point where your investments are large enough that compound growth alone will fund your full retirement, even if you never contribute another dollar. You just need to cover your living expenses until then.

What Does 'Coasting' Actually Mean?

Once you hit Coast FIRE, you can stop aggressively saving and investing. Your existing portfolio, left alone to grow at 7% annually, will compound to your full FIRE number by the time you hit traditional retirement age (65). You shift from wealth-building mode to just covering your current expenses — which is a much lighter financial burden.

How to Calculate Your Coast FIRE Number

The formula works backwards from your FIRE number. You take your target retirement portfolio, then discount it back to today using the expected rate of return and the number of years you have until traditional retirement age.

Coast FIRE Number = FIRE Target ÷ (1 + return rate)^years to retirement

• Example: FIRE target $1,500,000, retiring at 65, you're currently 35 (30 years), 7% return
• Coast FIRE number = $1,500,000 ÷ (1.07)^30 = $1,500,000 ÷ 7.61 = $197,000
• If you have $197,000 invested today at 35, you've hit Coast FIRE
• That $197k will grow to $1.5M by age 65 without another contribution

Why Coast FIRE Changes Your Relationship With Work

Once you hit Coast FIRE, you no longer need a high-paying job. You just need to cover your current expenses — which means you can take a lower-stress job, go part-time, freelance, or move somewhere cheaper. The pressure of 'I need to save 30% of my income' disappears.

Coast FIRE vs Barista FIRE vs Regular FIRE

• Regular FIRE: Full retirement now — portfolio covers all expenses indefinitely.
• Coast FIRE: Portfolio self-funds retirement by 65 — you just need income for current expenses.
• Barista FIRE: Part-time work covers current expenses + benefits, smaller portfolio required.
• Lean FIRE: Fully retired but on a tight budget, typically under $40k/year spending.

The Age Factor: Coast FIRE Numbers by Age

The earlier you reach Coast FIRE, the lower the number — because your investments have more time to compound. A 25-year-old with a $1.5M FIRE target needs only about $100,000 invested to have coasted. A 45-year-old with the same target needs closer to $550,000.

Risks to Watch With Coast FIRE

• Sequence of returns: A major market crash early in your coast period can derail the math.
• Expense inflation: If your lifestyle costs rise significantly, your FIRE target increases too.
• Healthcare: Covering health insurance between coast and full retirement is often the biggest cost.
• Temptation to spend investments: The money must stay invested — not touched — for the math to work.