The amount that, left to grow, funds retirement with no more saving.
Coast FIRE number
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Full FIRE number
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Surplus or shortfall
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Your breakdown
Updates live as you type| Step | Working | Result |
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The moment you can stop saving for retirement
Coast FIRE is a gentler cousin of full financial independence. Instead of asking how much you need to never work again, it asks a narrower question: how much do you need invested today so that, left completely alone to compound, it grows into your full retirement target by the time you stop working? Once you reach that figure you can stop adding to your retirement pot entirely. You still work, but only to cover today's living costs, because the retirement side is already on autopilot. For a Hong Kong professional juggling high rents and a long career ahead, hitting Coast FIRE early is a powerful psychological and financial release valve.
Two pieces of arithmetic stacked together
The tool builds the number in two steps. First it sets your full FIRE target by dividing your annual retirement spending by your withdrawal rate, the classic application of a safe-withdrawal figure such as 4 percent, which implies a pot 25 times your annual expenses. Then it discounts that target back to today using your expected return and the years until retirement, because money invested now has decades to grow. The result is the Coast FIRE number: smaller than the full target, often dramatically so, because compounding does the rest of the work. The withdrawal rate and the return are your assumptions, not guarantees, so treat the output as a planning guide rather than a promise.
A 35-year-old aiming to retire at 65
Take someone aged 35 planning to retire at 65, expecting $480,000 a year in retirement, using a 4 percent withdrawal rate and a 6 percent annual return. The full target is $480,000 divided by 4 percent, then discounted over 30 years of growth:
You would need about $2,089,322 invested today to coast to a $12 million pot by 65. With $800,000 so far, you are roughly $1,289,322 short, so the tool tells you to keep saving until your investments reach the Coast FIRE line. The striking part is the leverage: that $2,089,322 left untouched grows into the full $12 million purely through compounding, with no further contributions. The chart shows the small Coast FIRE seed today against the much larger target it grows into.
Where the assumptions bite
Coast FIRE is exquisitely sensitive to the return you assume, because it compounds over decades. Drop the expected return from 6 to 5 percent and the Coast FIRE number jumps, since a slower-growing seed must start larger. The figure is also in today's dollars and ignores inflation eroding your $480,000 of spending, so a conservative approach uses a real return, after inflation, rather than a nominal one. One genuinely helpful Hong Kong wrinkle: there is no capital gains tax and no tax on dividends here, so investment growth is not skimmed by tax along the way, which makes the compounding assumption cleaner than it would be in most countries. Re-run the tool whenever your spending plans or return outlook shift.
What changes the day you hit the number
Reaching Coast FIRE does not mean quitting work. It means you can redirect every dollar you were funnelling into retirement savings toward whatever else matters now, a career break, a lower-paid but better job, more time with family, or simply a lighter schedule. The retirement pot is already set to grow into the target on its own. The catch is discipline: the math only holds if you genuinely leave the invested money untouched for decades and resist raiding it. If you dip in, the compounding that does all the heavy lifting stalls, and the Coast FIRE promise quietly breaks.
Does my MPF count toward the Coast FIRE number?
Yes, your accrued MPF balance is retirement money and belongs in the current investments figure, alongside any personal investments and savings earmarked for retirement. Just remember MPF is locked until age 65 in most cases, so it cannot help with the living costs you still need to cover while coasting.
What is the difference between Coast FIRE and full FIRE?
Full FIRE means your pot is already large enough to live off entirely, so you can stop working today. Coast FIRE only means the retirement portion is on track without further saving; you still need an income to pay current bills. Coast FIRE arrives much earlier, which is why many people aim for it first.