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Using the FIRE Calculator.

Financial independence guide· 4% rule · Years to FIRE · Super toggle· All plans
General information only. Not financial advice. The FIRE calculator is a planning benchmark. Actual outcomes depend on investment returns, inflation, lifestyle changes, and many other factors that cannot be predicted. Consult a financial adviser before making retirement decisions.

What is FIRE?

FIRE stands for Financial Independence, Retire Early. The goal is to accumulate enough invested assets that the returns alone can fund your lifestyle indefinitely — making paid work optional. In Australia, the FIRE movement has grown rapidly as property-owning millennials look beyond the traditional retirement age of 65–67.

The FIRE number formula

Your FIRE number is the investment portfolio value needed to retire:

FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate

Example: $80,000 annual expenses ÷ 4% = $2,000,000 FIRE number
Example: $60,000 annual expenses ÷ 3.5% = $1,714,286 FIRE number

The withdrawal rate is the percentage of your portfolio you withdraw each year. At 4%, a $2M portfolio generates $80,000/year — and historically, the portfolio itself continues to grow, meaning it lasts indefinitely under most market scenarios.

The 4% rule — and its Australian caveats

The 4% rule comes from the Trinity Study (1998), which found that a portfolio of 50–75% equities with a 4% withdrawal rate survived all rolling 30-year periods in US market history from 1926–1995.

For Australian FIRE planners, some adjustments are worth considering:

  • Longer retirement horizon: retiring at 40 means a 50+ year retirement, not 30. Many Australian FIRE planners use 3.5% for extra margin.
  • Superannuation: if you retire before 60, you can't access super until preservation age. Your pre-60 FIRE number may be higher than the total number including super.
  • Australian market concentration: the ASX 200 is heavily weighted to banks and resources. A globally diversified portfolio may reduce sequence-of-returns risk.
  • Franking credits: Australian dividend imputation returns effective yield from franked dividends, which can effectively boost withdrawal capacity from Australian equity holdings.

How to use the FIRE Calculator in PortWorth

  1. Go to Analysis → Performance and select the FIRE tab.
  2. Enter Annual Expenses: what you would spend per year in retirement. Use your current spending as the baseline, then adjust for expected lifestyle changes (no commuting costs, but potentially more travel).
  3. Set the Withdrawal Rate. Default is 4%. Use 3.5% for conservative planning or 4.5% if you are willing to adjust spending in bad market years.
  4. Review your FIRE number. The ring chart shows your current net wealth (or investable assets) as a percentage of the FIRE number. The gap is how much more you need to accumulate.
  5. Enter Monthly Savings: how much you invest each month above living expenses.
  6. Set Expected Annual Return. Historical ASX 200 total return (including dividends) is approximately 9–10% per year before inflation. A globally diversified portfolio averages similar. Many planners use 7% in real terms (inflation-adjusted) for conservative projections.
  7. Read the projection: PortWorth shows the estimated year you reach your FIRE number, given your current portfolio, monthly savings, and expected return.

Super in the FIRE calculation

Toggle the Include Super switch to control whether superannuation is included in your "current portfolio" figure for the FIRE calculation:

  • Excluded: shows your FIRE number based only on accessible assets — shares, property equity, cash. This is your "bridge" requirement — what you need before super preservation age.
  • Included: shows total FIRE readiness including super, relevant for planning after age 60.

Many Australian FIRE planners track both numbers. The gap between them represents the "super gap" that must be bridged by accessible assets during early retirement.

Levers that move your FIRE date

ActionEffect
Reduce annual expenses by $10,000FIRE number drops by $250,000 (at 4%)
Increase monthly savings by $500Significant — varies by current portfolio and return
Increase expected return by 1%Can move FIRE date forward 2–4 years
Lower withdrawal rate from 4% to 3.5%FIRE number increases by ~14%
Include property equityCan dramatically close the gap if you plan to downsize

Frequently asked questions

Does the FIRE calculator account for inflation?

The calculator uses nominal returns by default. To get a real (inflation-adjusted) projection, enter your expected return minus expected inflation (e.g. 9% return − 3% inflation = 6% real return). The 4% rule itself was derived from real (inflation-adjusted) returns in the original Trinity Study.

What about the Age Pension?

The Age Pension (currently starting at 67) is not included in the FIRE calculation by default. If you plan to rely partly on the Age Pension, you can reduce your FIRE number by the expected annual pension entitlement. Note that means-tested pension thresholds may make FIRE wealth incompatible with pension eligibility.

Can I run a Monte Carlo simulation on my FIRE projection?

Yes. The Monte Carlo simulation on the Performance tab lets you run thousands of randomised return paths using your expected return and volatility. It shows the probability distribution of portfolio values over time — far more realistic than a single-rate linear projection. See the Portfolio Simulations guide.

How far away is FIRE?

Find out your number.

PortWorth's FIRE calculator runs against your actual portfolio in real time. Join the waitlist.

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