Most people know about FIRE — the point where your investments support full retirement. But Coast FIRE is different, and in some ways more powerful: it's the point where you never have to save another dollar for retirement, because the math will handle it for you.
7 min read · startinvesting.ai
You've hit Coast FIRE when your current savings will compound to your full FIRE number by retirement age — even if you never invest another dollar.
Here's a concrete example: say your FIRE number is $1,500,000 (enough to withdraw $60,000/year at 4%). You're 35 years old and have $197,000 invested. At a 7% real return, that $197,000 will grow to approximately $1,500,000 by age 65 without any additional contributions.
You've coasted. The retirement savings problem is solved. You still need to work to pay your current bills — but you no longer need to save for the future. Every dollar you earn from this point only needs to cover today's expenses.
The Coast FIRE calculation is straightforward. You need to find the present value of your future FIRE number:
Coast FIRE Number = FIRE Target ÷ (1 + r)^n
Where r = real annual return rate (typically 0.07), n = years until retirement
Example: FIRE target = $1,500,000. Current age = 30. Retirement age = 65 (35 years). Real return = 7%.
Coast FIRE Number = $1,500,000 ÷ (1.07)^35 = $1,500,000 ÷ 10.68 = approximately $140,000
If you have $140,000 invested at 30, you can stop making retirement contributions entirely and still reach $1.5M by 65.
To reach a $1,500,000 portfolio by age 65 at a 7% real return — with no further contributions:
| Your Age | Years to Grow | Coast FIRE Number |
|---|---|---|
| Age 25 | 40 years | $100,000 |
| Age 30 | 35 years | $140,000 |
| Age 35 | 30 years | $197,000 |
| Age 40 | 25 years | $276,000 |
| Age 45 | 20 years | $388,000 |
| Age 50 | 15 years | $543,000 |
To reach $1.5M by age 65 at 7% real return, stopping all contributions at the listed age. Your FIRE target may differ.
Before hitting Coast FIRE, every career decision is tied to retirement savings. You need to stay in the high-income job, take the promotion, accept the demanding project — because you're still building the nest egg.
After hitting Coast FIRE, your only financial requirement from work is to cover today's living expenses. A $40,000/year lifestyle? Any job that pays $40,000+ works. Want to start a business? Take the lower-paying but more meaningful role? Work part-time? All viable — because you don't need the work to fund retirement.
This is why many personal finance thinkers argue that Coast FIRE is the milestone worth obsessing over — not full FIRE. Full FIRE requires a much larger number and may be decades away. Coast FIRE can be reached with a few years of aggressive saving early in your career.
The Coast FIRE number is lower the younger you are — which means the strategy is to invest aggressively early and then ease off. A few years of high savings rate in your 20s can eliminate the need to save for retirement in your 30s and beyond.
Practical approach: if you can save aggressively for 5–8 years in your mid-to-late 20s, you may reach your Coast FIRE number before 35. From that point, you only need income that covers your actual lifestyle — not income that also funds a retirement account.
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Open FIRE Calculator →What is Coast FIRE?
Coast FIRE is when you've saved enough money that — if you never invest another dollar — your existing portfolio will compound to your full FIRE number by retirement age on its own. You've 'coasted' to financial independence: you just need to cover your current living expenses, not save anything extra.
How do you calculate your Coast FIRE number?
Coast FIRE Number = FIRE Target ÷ (1 + real return rate)^years until retirement. Example: if your FIRE number is $1.5M, you're 35, and you want to retire at 65, your Coast FIRE number at 7% real return is $1,500,000 ÷ (1.07)^30 = approximately $197,000.
What's the difference between Coast FIRE and regular FIRE?
Regular FIRE means your portfolio is large enough to support full retirement now — you can stop working immediately. Coast FIRE means your portfolio will get to that point in the future without additional contributions — but you still need to work to cover current expenses, just not to save for retirement.
What's Barista FIRE?
Barista FIRE (also called Semi-FIRE) is when you leave a high-paying stressful job but take low-stress part-time work to cover living expenses — often including health insurance. It's named after the stereotype of leaving corporate work to be a barista. It's related to Coast FIRE: once you hit Coast FIRE, you only need to earn enough to live on, not save.
Is Coast FIRE worth aiming for?
For many people, hitting Coast FIRE is the most freeing milestone in personal finance — more than FIRE itself. Once you've coasted, the retirement savings problem is effectively solved. You can shift your career focus from maximizing income to maximizing meaning, flexibility, or balance, knowing the long-term math is already taken care of.
What return rate should I use for my Coast FIRE calculation?
Use a real (inflation-adjusted) return rate — typically 5–7%. The S&P 500 has historically returned ~10% nominal, which is roughly 7% after inflation (using the Fisher equation). Using 7% is a reasonable baseline; 5–6% is more conservative and accounts for lower expected future returns.
For educational purposes only. Not financial advice. Coast FIRE calculations assume consistent investment returns that are not guaranteed. All projections are in real (inflation-adjusted) dollars. Past market performance does not guarantee future results.