Save Hard Now or Coast to Retirement?
How much do you need before you can stop saving for retirement and let compound growth do the rest? Find your Coast FIRE number.
Coast FIRE is the point where your investments are large enough to grow into your full retirement number on their own — without saving another dollar. You're not retired yet, but compound growth will get you there by your target date.
Once you hit Coast FIRE, you still need income to cover current expenses, but you no longer need to save for retirement. This means you could take a lower-paying job, go part-time, freelance, start a business, or take a sabbatical — without jeopardizing your future.
The chart above shows two paths: keep saving (green) shows your portfolio if you continue saving at your current rate. Coast now (blue) shows what happens if you stop saving today and let growth do the work. The dashed line is your FIRE target.
Coast FIRE: The Most Underrated Milestone
Most people think of financial independence as all-or-nothing: either you're working full time or you're fully retired. Coast FIRE is the milestone in between — the point where you've saved enough that compound growth alone will fund your retirement, even if you never invest another dollar.
How Coast FIRE Works
The math is straightforward. If you need $1.25 million at 65 (based on $50K/year expenses and a 4% withdrawal rate), and you expect 8% annual returns, you can work backwards to find how much you need at any earlier age for growth alone to reach that target.
At age 30, you'd need about $92,000 — because $92K growing at 8% for 35 years reaches $1.25M. At age 35, you'd need about $135,000. At 40, about $198,000. The younger you are, the less you need, because time does more of the work.
Why Coast FIRE Changes Everything
Once you hit Coast FIRE, the pressure valve releases. You still need to earn enough to cover current expenses, but the relentless need to maximize savings disappears. This opens up possibilities that felt impossible before: switching to a less stressful job, going part-time, starting a passion project, taking a gap year, or moving somewhere cheaper.
Many people find that the years between Coast FIRE and full retirement are the best of their careers — because they're working by choice, not necessity.
Coast FIRE vs Regular FIRE
Regular FIRE means you have enough to cover expenses forever — you can stop working entirely. Coast FIRE means you have enough that growth handles retirement — but you still need to cover current expenses. It's a waypoint, not the destination, but it's a life-changing waypoint.
For most people, Coast FIRE arrives 10–15 years before full FIRE. That's a decade of reduced financial pressure that many people never realize they're close to achieving.
The Biggest Risk
Coast FIRE relies heavily on investment returns. If the market delivers 8% average returns, the math works beautifully. But a prolonged bear market or a lost decade (like 2000–2010) could leave you short. Build in a margin of safety: aim for 10–20% more than your calculated coast number, or use a more conservative return estimate like 6–7%.
Frequently Asked Questions
Can I really stop saving once I hit Coast FIRE?
Technically yes, but most people don't stop completely. They reduce savings from aggressive levels to a comfortable amount. Even small continued contributions provide a safety margin against lower-than-expected returns.
What return rate should I use?
Use 7–8% for a stock-heavy portfolio. If you want to be conservative (recommended), use 6–7%. The higher the return you assume, the lower your coast number — but the more risk you're taking that actual returns will fall short.
What if my expenses change in retirement?
Many people spend less in retirement (no commute, no work wardrobe, potentially no mortgage). Others spend more on healthcare and travel. Adjust the retirement expenses slider to match your expected lifestyle. A common rule of thumb is 80% of pre-retirement expenses.
Does this include Social Security?
No. If you expect to receive Social Security, it reduces the amount your portfolio needs to cover — effectively lowering both your FIRE number and your Coast FIRE number. You can adjust by reducing your retirement expenses by your expected Social Security benefit.