Coast FIRE is the quietly popular middle path of the FIRE movement. You save hard for a while, hit a specific number, and then stop contributing. From that point on, compound growth alone is enough to carry your portfolio to your full retirement target by age 60 or 67. You keep working, but you never need to save for retirement again.
In Australia, Coast FIRE has a few quirks that change the maths. Super preservation, the Age Pension, and our tax treatment of long-term capital all shift the picture compared with the US version you will see on most FIRE blogs.
Coast FIRE in one sentence
How Coast FIRE actually works
The maths is straight compound interest in reverse. Pick a full FIRE number, a retirement age, and an expected real return (inflation-adjusted), then work backwards to today.
Example: say you want $1.5M (in today's dollars) by age 60 and expect a 5% real return. You are currently 35.
- Years of growth remaining: 25
- Growth multiplier at 5% real: 1.0525 ≈ 3.39×
- Coast FIRE number today: $1,500,000 ÷ 3.39 ≈ $442,500
Hit $442,500 invested in productive assets (shares, super, ETFs) at 35 and you are technically Coast FIRE for a 60-year-old finish line. You can stop saving for retirement and redirect that cashflow wherever you like.
Rough Coast FIRE targets by age
These are ballpark numbers for a $1.5M (today's dollars) target at age 60, assuming 5% real returns. Real returns vary, so treat these as directional, not a promise.
| Age today | Years to 60 | Coast FIRE number |
|---|---|---|
| 25 | 35 | ~$272,000 |
| 30 | 30 | ~$347,000 |
| 35 | 25 | ~$443,000 |
| 40 | 20 | ~$565,000 |
| 45 | 15 | ~$722,000 |
| 50 | 10 | ~$921,000 |
The Australian twist: super vs non-super
Most Coast FIRE content assumes a single pooled portfolio. In Australia the split between super and non-super matters a lot. Super has a long runway, favourable tax, and is preserved until age 60 for most people. Non-super is accessible but taxed differently. For Coast FIRE purposes:
- Super is ideal for coasting. Your employer keeps paying the Super Guarantee (12% since 1 July 2025 — the final legislated rate). Even if you stop making voluntary contributions, employer SG keeps flowing into your account and compounding.
- Non-super balances decide when you can retire. If your goal is retiring at 45, 50, or 55, you still need a bridge portfolio outside super. Coast FIRE on super alone means coasting to 60, not coasting to early retirement.
- Check the full picture. It is possible to be Coast FIRE on a full balance but have a non-super bridge that will not last between early retirement and age 60. Model both sides separately.
Why people choose Coast FIRE
Full FIRE is a big commitment: years of above-average saving rates and often lifestyle compromises. Coast FIRE is a softer landing:
- Psychological relief. Once you hit Coast FIRE, the pressure to optimise every dollar stops. You can spend what you earn and still retire fine.
- Career flexibility. Take a lower-paid job you love, drop a day a week, go freelance, or start a business. You only need to cover current expenses.
- Family stage fit. For many people, peak kid-raising years happen right when they hit Coast FIRE. It frees up money for school fees, travel, housing.
- Optionality. Coast FIRE is a stepping stone, not a destination. Plenty of people hit Coast, keep saving anyway, and end up at full FIRE a decade later.
Traps to watch for
- Lifestyle creep. The whole point of Coast FIRE is you get to spend what you earn. That is also how people end up needing to save again five years later. Pick a spending level and hold it.
- Ignoring Age Pension assets test. A higher savings balance reduces Age Pension eligibility. For modest Coast FIRE targets, the pension is often part of the plan and should not be left out.
- Forgetting inflation. Coast FIRE numbers are usually quoted in today's dollars. Make sure your mental FIRE target is also in today's dollars or you will miss by 20%+.
- Super cap surprises. If you are Coast FIRE and stop voluntary super contributions, you may lose access to carry-forward concessional caps over time. Keep an eye on the $500,000 total super balance threshold that unlocks carry-forward.
How ProjectFi models Coast FIRE
ProjectFi runs the full three-phase model: accumulation, pre-super (gap) phase, and post-super. To test a Coast FIRE plan, set your voluntary contributions and non-super savings rate to zero from your target Coast date and see whether:
- Your super still reaches your FIRE target by age 60
- Your non-super bridge still supports the years between early retirement (if any) and 60
- Your Monte Carlo success probability stays above 85%
That last one matters. Coast FIRE is a compound-growth bet, and compound growth has a wide band of plausible outcomes. A Coast plan that works in the average case but fails in 40% of simulations is not really a plan.
Try it yourself
See if you are Coast FIRE today
Set up a scenario with your current balances, drop contributions to zero, and watch the projection. ProjectFi will tell you the earliest age you can stop saving and still reach your FIRE number.
Run the numbersCoast FIRE vs Barista FIRE
Coast FIRE and Barista FIRE get confused often. The distinction is simple:
- Coast FIRE: your portfolio still grows without contributions, and you earn enough from work to cover expenses. You do not touch the portfolio until retirement.
- Barista FIRE: your portfolio covers part of your expenses via partial withdrawals, and you work part-time to cover the rest. You touch the portfolio during the coast years.
Both are valid. Coast FIRE is usually easier to plan because you never draw down early. Barista FIRE requires careful withdrawal modelling to avoid eating into your compounding base.
The bottom line