1. What is Coast FIRE?
Coast FIRE (Financially Independent, Retire Early) is the point where your existing investments, growing at compound returns, will reach your retirement corpus on their own — without any further contributions.
Once you've hit your Coast FIRE number, you no longer need to save for retirement. You can "coast" — keep working to cover your current living expenses — and let the portfolio grow untouched. You'll still reach financial independence at your target retirement age.
- FIRE: You have enough capital to never work again.
- Coast FIRE: You have enough capital that you won't need to save any more — but you still need to work to cover current expenses.
- Barista FIRE: A middle path — you have some capital and take a lower-paying job to cover expenses.
2. The Coast FIRE formula
The Coast FIRE number is calculated in two steps. First, find your retirement corpus:
Retirement corpus = Annual expense × [1 − (1 + realReturn)^−n] ÷ realReturn
Where realReturn is post-retirement return minus inflation, and n is the number of retirement years. Then discount that corpus back to today:
Coast FIRE = Retirement corpus ÷ (1 + expectedReturn)^(years to retire)
This is exactly what the calculator does. The result is the amount you need invested today, with no further saving, for the compounding to carry you to retirement.
3. A worked example
A 32-year-old who plans to retire at 60 (28 years away) with:
- Monthly expenses at retirement: ₹75,000 (in today's money)
- Inflation: 6% p.a.
- Post-retirement return: 7% p.a.
- Life expectancy: 85 (25 years in retirement)
- Pre-retirement return: 12% p.a.
Step 1 — Monthly expense at 60:
- ₹75,000 × 1.06^28 = ₹3,83,000/month (₹46 lakh/year)
Step 2 — Corpus needed at 60 (25 years of retirement at real return ~0.94%):
- ₹46 lakh × [1 − 1.0094^−25] ÷ 0.0094 ≈ ₹10.3 crore
Step 3 — Coast FIRE number today:
- ₹10.3 Cr ÷ 1.12^28 = ₹42.6 lakh
So a 32-year-old needs roughly ₹42.6 lakh invested today. If they have ₹42.6 lakh invested at 12% and never add another rupee, they'll have ₹10.3 crore by age 60.
✓ Once you hit Coast FIRE, any further saving is optional. You can choose to keep saving to reach financial independence even earlier, or you can redirect the surplus to lifestyle upgrades, a career change, or a sabbatical.
4. Why Coast FIRE is a powerful milestone
Coast FIRE is often more achievable than full FIRE, and it unlocks several advantages:
- Career flexibility: You can take a lower-paying job you enjoy, start a business, or work part-time — without sacrificing your retirement.
- Reduced pressure: The knowledge that retirement is funded lets you make better long-term career decisions.
- More optionality: You can redirect your monthly saving toward other goals — a home, education, or travel.
- Lower stress: You're no longer dependent on the next promotion or bonus.
- Faster to reach: The Coast FIRE number is 40%–50% of the full FIRE number in most scenarios.
5. When NOT to Coast
Coast FIRE isn't for everyone. Consider not coasting if:
- Your income is volatile: If your job might end, having the full FIRE corpus gives more security.
- Your expenses might rise: Health costs, children's education, or supporting parents can consume more than planned.
- You want to retire early: Coast FIRE assumes you work to standard retirement age. If you want to retire at 45, you need full FIRE.
- You're close to retirement: If you're 55, the compounding window is short — you're essentially at full FIRE already.
- You enjoy your work: If you love your career, there's no need to plan around stopping.
- The market underperforms: A decade of low returns can push your Coast FIRE date out by years. Buffer with a conservative assumption.
⚠️ Coast FIRE assumes a smooth return path. A prolonged bear market early on can derail the plan. Use conservative return assumptions (10%–11%) and review annually.
6. Coast FIRE vs. traditional FIRE
Both aim for financial independence, but they take different paths:
| Metric | Coast FIRE | Traditional FIRE |
|---|---|---|
| Portfolio needed today | 30%–50% of FIRE number | 100% of FIRE number |
| Still need to work? | Yes — to cover current expenses | No |
| Stop saving? | Yes | Yes (you're done) |
| Retire at target age? | Yes | Yes |
| Retire early? | No | Yes |
| Years to reach | 8–15 years typically | 15–25 years typically |
7. How to use Coast FIRE in practice
- Compute your Coast FIRE number using this calculator. Track it as a milestone.
- Keep saving until you reach it. Don't coast early — the difference between "almost there" and "there" is significant.
- Reach it, then decide. Once you've hit the number, you can redirect your monthly saving. Some people keep saving to retire early. Others spend it on lifestyle or start businesses.
- Review annually. Changes in return assumptions, inflation, or spending expectations shift your Coast FIRE number. Recalculate every year.
- Build a buffer. Aim for 10%–20% above your calculated Coast FIRE number to absorb market volatility.
8. Common mistakes to avoid
- Coasting too early: If you're within 2–3 years of the number, finish the job. Small shortfalls compound into large gaps.
- Using aggressive return assumptions: 12% returns may not materialise. Use 10%–11% for planning.
- Ignoring inflation: A "₹75,000 expense" 30 years from now is not ₹75,000 in today's money. Inflate first.
- Underestimating retirement length: Plan to 90, not 80. Lifespans are increasing.
- Forgetting healthcare: Medical costs inflate 10%+ per year. Add a buffer for healthcare beyond general inflation.
- Not accounting for taxes: Post-tax returns are what actually compounds. Adjust your return assumption.
- Coasting in the wrong account: Keep compounding tax-advantaged accounts (like EPF, PPF, NPS) untouched; use taxable accounts if you need money.
9. Final thoughts
Coast FIRE is a powerful concept that reframes the financial independence journey. Instead of asking "when can I stop working?", Coast FIRE asks "when can I stop saving?" — a much easier question to answer, with a much nearer milestone.
Reaching Coast FIRE doesn't mean you have to stop saving or change your career. It means you've given yourself the freedom to make those choices without worrying about retirement. That's a real form of wealth.
Use this calculator to find your Coast FIRE number. Track your progress annually. When you reach it, celebrate — you've crossed one of the most meaningful milestones in personal finance.
