The pot you need and the years to reach it.
FIRE number
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Years to FI
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Still needed today
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The number behind the 4 percent rule
Financial independence boils down to one figure: a pot big enough that its income covers your spending for good. The most quoted shorthand is the 4 percent rule, which says you can draw 4 percent of your pot in the first year and adjust for inflation after that, with a strong chance the money lasts decades. Turn that around and your target is annual spending divided by 0.04, which is 25 times what you spend in a year. This calculator builds the target from your spend and withdrawal rate, then projects how many years of saving and growth it takes to get there.
Choosing your withdrawal rate
The 4 percent figure came from US market history, and plenty of people argue it is a touch optimistic for a long early retirement. Drop the rate to 3.5 percent and your target jumps, because you are dividing by a smaller number. At 3.5 percent you need roughly 28.6 times spending rather than 25. There is no single correct answer. A lower rate buys a bigger safety margin against poor markets early in retirement, at the cost of working a little longer to build the larger pot.
Sequence of returns risk is the reason that margin matters. If a market crash lands in the first few years after you stop work, you are selling assets while they are depressed to fund living costs, and the pot may never recover. A retiree who hits a downturn at 45 is far more exposed than one who hits the same downturn at 70 with a State Pension already flowing. Many Irish early retirees address this by holding a cash buffer of one to three years of spending, so they can pause withdrawals from the invested pot when markets fall and let it heal.
From €100,000 to €1 million
Take someone who spends 40,000 euro a year, already holds 100,000 euro, adds 20,000 euro a year, and expects a 5 percent return. At a 4 percent withdrawal rate the target is 1,000,000 euro, which is 25 times the annual spend. Starting from 100,000 euro, the projection reaches that target in 22 years.
| Input | Figure |
|---|---|
| Annual spending | €40,000 |
| Withdrawal rate | 4% |
| FIRE number (25x spend) | €1,000,000 |
| Starting savings | €100,000 |
| Added each year at 5% growth | €20,000 |
| Years to reach the target | 22 |
The curve below shows the pot accelerating as compounding takes over, crossing the 1,000,000 euro line at year 22.
The Irish wrinkle: locked pensions and exit tax
Two local realities make Irish FIRE different from the US version this rule came from. First, pension money is locked away. An occupational scheme you have left can often be accessed from age 50, while a PRSA generally waits until 60. So if you plan to stop work at 45, a large slice of your pot may be untouchable for years, and you need taxable savings outside the pension to bridge the gap. Second, growth inside life-wrapped funds and most ETFs is taxed at the 41 percent exit tax rate, which quietly drags on returns and means your real after-tax growth is lower than the headline 5 percent. Factor both in, because a pot that looks big enough on paper can still leave you short of accessible cash in the early years.
Does the FIRE number account for the State Pension?
No, this target is built purely from your own pot. The State Pension, currently a full personal rate of about 289 euro a week, only starts at 66 and is taxable income. If you expect to qualify, it reduces how much of your own spending the pot must cover from that age on, so a strict early retiree often needs the biggest pot in the years before 66 and a smaller drawdown afterwards.
Should I aim for Coast FIRE instead of full FIRE?
Coast FIRE is a softer target: you save hard early until your pot, left to compound, will grow into your full number by normal retirement age without another cent added. From that point you only need to cover current spending, not keep saving. It suits people who want to ease off the savings pressure or switch to lower-paid work they enjoy, rather than retire outright.