📈 Calculate Your Coast FIRE Number
Your Coast FIRE Number by Age
How much you need invested at each age so compound growth does the rest:
| Age | Coast FIRE Number | Growth Years |
|---|
What Is Coast FIRE?
Coast FIRE (also called Coast FI) is the point at which you have enough money invested that compound growth alone will grow your portfolio to your full FIRE number by your desired retirement age — even if you never invest another dollar.
Once you reach Coast FIRE, the pressure to aggressively save disappears. You still need to work to cover your current living expenses, but you no longer need to save for retirement. This opens the door to:
- Switching to lower-paying but more meaningful work
- Working part-time or freelancing
- Taking career risks you couldn’t before (startups, creative work, travel)
- Reducing work stress knowing retirement is mathematically secured
The Coast FIRE Formula
Coast FIRE Number = FIRE Number ÷ (1 + real return)years until retirement
Example: $1,250,000 ÷ (1.07)30 = $164,179
Coast FIRE Number by Age (Quick Reference)
The table below shows approximate Coast FIRE numbers needed at each age, assuming a $50,000/year retirement expense, 4% SWR ($1.25M FIRE number), and 7% real returns:
| Current Age | Retire at 60 | Retire at 55 | Retire at 65 |
|---|---|---|---|
| 25 | $125,527 | $170,690 | $92,340 |
| 30 | $176,021 | $239,395 | $129,511 |
| 35 | $246,842 | $335,608 | $181,571 |
| 40 | $346,102 | $470,578 | $254,612 |
| 45 | $485,367 | $659,891 | $357,001 |
| 50 | $680,583 | $925,349 | $500,574 |
Coast FIRE vs. Full FIRE vs. Barista FIRE
| Concept | Meaning | Do You Still Work? |
|---|---|---|
| Full FIRE | Portfolio covers all expenses via withdrawals now | No (optional) |
| Coast FIRE | Portfolio will grow to FIRE number without more contributions | Yes — to cover current expenses |
| Barista FIRE | Investments cover most expenses; part-time work covers the rest + insurance | Yes — part-time for insurance/gap |
Why Coast FIRE Is So Powerful
Coast FIRE is often the first major FIRE milestone people reach, and it fundamentally shifts your relationship with work:
The Psychological Shift
Once you know that retirement is mathematically inevitable — that compound growth will carry you there regardless — the pressure to maximize income evaporates. You can choose work for fulfillment rather than financial necessity. Many people report this as the single most freeing moment in their FIRE journey.
- It’s achievable earlier. A 25-year-old needs just ~$126K to Coast FIRE (vs. $1.25M for full FIRE).
- It reduces burnout. Knowing you can switch to lower-stress work is a powerful release valve.
- It’s flexible. You can Coast until 55, 60, or 65 — each target drastically changes the required amount.
- It works at any income level. Even saving aggressively for 5–7 years and then coasting is viable.
Frequently Asked Questions
Coast FIRE means you have enough invested that compound growth alone will reach your retirement target by your desired age — without investing another dollar. You still work to cover current expenses, but you no longer need to save for retirement.
Coast FIRE Number = FIRE Number ÷ (1 + real return rate)^(years until retirement). For example, with a $1.25M FIRE number, 7% returns, and 30 years to go: $1,250,000 ÷ (1.07)^30 = ~$164,000.
If real returns average 5% instead of 7%, your Coast FIRE number increases significantly. Use this calculator with different return rates to stress-test. You can also continue making small contributions even after Coast FIRE as a buffer, or extend your target retirement age by a few years.
Yes — time is the most powerful variable. A 25-year-old targeting $1.25M at age 60 needs about $126,000 invested (assuming 7% real returns). By saving aggressively for 3–5 years after starting your career, Coast FIRE in your late 20s is achievable on a solid middle-class income.