What is financial independence?

Financial independence (FI) is the point where your investments are large enough that the income they can safely produce covers your living costs, so paid work becomes optional. It is the core idea behind the FIRE movement.

How is the FI number worked out?

A common rule of thumb is 25 times your annual spending, which matches a 4% safe withdrawal rate. So if you spend $50,000 a year, your FI number is around $1.25 million. This calculator finds the age your savings reach that number.

Is the 4% rule reliable?

It is a guide, not a guarantee. It was based on historical US data over 30 years; a longer retirement, lower returns or high inflation can make a lower rate safer. Treat the result as a target to aim for, not a promise.

Financial Independence Age Calculator

This New Zealand calculator estimates the age at which your investments could cover your living costs, so paid work becomes optional. It uses your target spending and a safe withdrawal rate to set a financial independence (FI) number, then projects your savings forward to find when you reach it. You enter your age, savings, contributions, return and spending, and the tool shows your FI number and the age you hit it.

Your age now

Current investments

Invested per month

Return p.a.

Annual spending

Safe withdrawal rate

estimated financial independence age

Your FI number$0

Years away-

FI number is your annual spending divided by the safe withdrawal rate (25x spending at 4%). Projects current investments plus monthly contributions at your return until they reach the FI number. A guide using assumptions, not a guarantee; NZ Super may also help from 65. Estimate only, not financial advice.

How it works

The calculator sets your FI number as your annual spending divided by the safe withdrawal rate, the size of portfolio that could sustainably fund your spending. It then grows your current investments plus your monthly contributions at your expected return, month by month, until they reach that number, and reports the age and how many years away that is.

Worked example

Spending $50,000 a year at a 4% withdrawal rate gives an FI number of $1.25 million. With $120,000 invested, $1,500 a month and a 6% return, you would reach it in your early 50s, sooner if you save more or spend less, later if returns are lower.

Related calculators

FIRE Number Calculator: your FI number.
Coast FIRE Calculator: coasting to FI.
Retirement Calculator: plan retirement.
Passive Income Target Calculator: income goals.

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