Imagine reaching a point where you never have to save another dollar for retirement — and you'll still be financially independent by your target age. That's Coast FIRE. It's one of the most psychologically powerful milestones in the FIRE journey because it fundamentally changes your relationship with money. Once you're coasting, your only job is to cover current expenses. The future is already funded.
What Is Coast FIRE?
Coast FIRE means you have enough money invested today that — without adding another dollar — it will compound to your full FIRE number by the time you want to retire. You "coast" to retirement on the growth already locked in.
The key insight: money invested at 25 has 40 years to grow before traditional retirement age. At 7% annual returns, $1 becomes $14.97 in 40 years. That incredible multiplier means you need far less invested today than you'll need at retirement.
Coast FIRE Number = FIRE Number ÷ (1 + r)^n
Where r = expected annual return and n = years until target retirement age. This is simply the present value of your future FIRE number — how much you need invested today for it to grow to your FIRE number by retirement.
Worked Example: The $2M Target
Let's use a detailed example. Jordan is 35, wants to retire at 65 (30 years away), and needs $2,000,000 at retirement (spending $80,000/year at 4% SWR). Assuming 7% average annual returns:
Coast FIRE Number = $2,000,000 ÷ (1.07)^30
= $2,000,000 ÷ 7.612 = $262,800
If Jordan has $262,800 invested today at 35 and never contributes another dollar, that portfolio will grow to approximately $2,000,000 by age 65. Jordan has officially hit Coast FIRE.
What if Jordan is only 25? Coast FIRE number = $2,000,000 ÷ (1.07)^40 = $2,000,000 ÷ 14.97 = $133,600. The earlier you reach Coast FIRE, the lower the number — because time is doing more of the work.
Coast FIRE Numbers by Age and Target
Assuming 7% annual returns and a retirement target age of 65:
| Current Age | Years to 65 | For $1M Target | For $1.5M Target | For $2M Target | For $3M Target |
|---|---|---|---|---|---|
| 25 | 40 | $66,800 | $100,200 | $133,600 | $200,400 |
| 30 | 35 | $94,000 | $141,000 | $188,000 | $282,000 |
| 35 | 30 | $131,400 | $197,100 | $262,800 | $394,200 |
| 40 | 25 | $184,200 | $276,300 | $368,400 | $552,600 |
| 45 | 20 | $258,400 | $387,600 | $516,800 | $775,200 |
| 50 | 15 | $362,400 | $543,600 | $724,800 | $1,087,200 |
A 30-year-old with $188,000 invested has hit Coast FIRE for a $2M retirement target — even if they never contribute another dollar. For many people, this milestone arrives 10–15 years before full FIRE.
Why Coast FIRE Is Such a Powerful Milestone
Coast FIRE changes the game in several ways:
- It eliminates retirement savings stress. Once coasting, you only need to earn enough to cover today's bills. You can take a pay cut, change careers, work fewer hours, or move to a lower cost-of-living area without affecting your retirement trajectory.
- It unlocks career flexibility. If you hate your job but love your field at a different company that pays 20% less — you can make that move. The retirement math doesn't care.
- It creates a psychological shift. Many people report that hitting Coast FIRE is more liberating than hitting full FIRE, because it removes the pressure that distorts daily decision-making for years.
- It's achievable earlier than expected. For high earners or aggressive savers, Coast FIRE can arrive in their late 20s or early 30s — decades before traditional retirement.
What to Do With Income After Reaching Coast FIRE
Once you're coasting, your income only needs to cover current expenses. This creates genuine options most people never experience in their working lives:
- Work part-time: A 25-hour week at $25/hour generates $32,500/year — enough to cover a modest lifestyle in many cities.
- Switch to meaningful but lower-paying work: Teaching, non-profit work, freelancing, seasonal work — all become viable when you're not chasing a savings target.
- Start a business: You can take the income risk of entrepreneurship when the stakes are "can I cover expenses this month" rather than "can I fund my entire retirement."
- Keep saving aggressively: If you enjoy your work, continuing to save hard after Coast FIRE accelerates the arrival of full FIRE. Many people discover that Coast FIRE is a waypoint, not a stopping point.
Coast FIRE math assumes consistent 7% real returns. If markets deliver 4–5% over the next 20 years instead, your "coasted" portfolio may fall short. The main risk mitigation: don't stop saving the moment you hit the Coast FIRE number. Give yourself a 10–20% buffer before declaring yourself coasted. Coast FIRE at $230k when the formula says $188k, and you're building in real resilience against market underperformance.
Coast FIRE vs. Full FIRE: The Timeline Difference
Here's how the timelines typically compare for someone saving aggressively from age 25:
- Coast FIRE: Often achievable by age 30–35 for high earners saving 30–40% of income
- Barista FIRE / Lean FIRE: Often 5–10 years after Coast FIRE
- Full FIRE: Typically 15–25 years of aggressive saving from a zero base
The full Coast FIRE strategy guide explores the nuances of planning your coast phase, including how to verify your Coast FIRE status each year as return assumptions change.
Enter your current portfolio balance, expected return, and target retirement age into MyFIRE's planner. It will tell you whether you've already hit Coast FIRE and — if not — exactly how much more you need to save before you can stop contributing.
This article is for educational purposes only and does not constitute financial advice. MyFIRE is not a registered investment advisor. Always consult a qualified fee-only CFP before making retirement decisions.
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