What is the FIRE movement?
FIRE — financial independence, retire early — is a movement built around the idea that by saving and investing a large portion of your income, you can accumulate enough wealth to make paid employment optional well before the traditional retirement age. The movement gained momentum through online communities and blogs in the 2010s, but its core principles — spend less than you earn, invest the difference, let compound growth do the work — are timeless.
The "retire early" part of FIRE is often misunderstood. For most FIRE practitioners, early retirement does not mean sitting idle. It means having the financial freedom to pursue work, projects, or activities on your own terms, without being dependent on a salary to cover your living costs.
FIRE variants
Not everyone pursuing FIRE has the same target lifestyle or risk tolerance. Over time, the community has developed several recognised variants to reflect different approaches.
Lean FIRE
Lean FIRE involves achieving financial independence on a minimal budget, typically below the median household spending. In an Australian context, this might mean targeting annual expenses of $40,000 to $50,000, resulting in a FI number of $1,000,000 to $1,250,000. Lean FIRE requires a frugal lifestyle and leaves less margin for unexpected expenses or lifestyle changes.
Regular FIRE
Regular FIRE targets a comfortable middle-class lifestyle in retirement. Annual expenses might range from $60,000 to $100,000, with a corresponding FI number of $1,500,000 to $2,500,000. This is the most common target for professionals who want to maintain their current standard of living without working.
Fat FIRE
Fat FIRE is for those who want to maintain a higher standard of living in retirement, with annual expenses above $100,000. For a household spending $150,000 per year, the FI number would be $3,750,000. Fat FIRE typically requires a high income, a long accumulation phase, or both. Many high-income professionals in Australia naturally gravitate towards this variant.
Barista FIRE
Barista FIRE (sometimes called semi-retirement) means having enough invested to cover most of your expenses, while working part-time to cover the gap and maintain access to benefits. For example, you might have $1,500,000 invested and work part-time earning $30,000 per year to supplement your portfolio withdrawals. This approach reduces the total savings needed and provides a social outlet and sense of purpose.
Our compare scenarios feature lets you model these different variants side by side, so you can see how each approach affects your timeline and required savings.
The 4% rule and its origins
The 4% rule is the cornerstone of most FIRE calculations. It states that if you withdraw 4% of your portfolio in the first year of retirement and adjust that amount for inflation each subsequent year, your portfolio has a high probability of lasting at least 30 years.
This rule comes from research by William Bengen (1994) and the subsequent Trinity Study (1998), which analysed historical US stock and bond returns. The studies found that a 50/50 or 75/25 stock/bond portfolio could sustain a 4% withdrawal rate in the vast majority of 30-year periods, even accounting for major market downturns.
However, the 4% rule has limitations. It was derived from US market data, which has historically outperformed many other markets. It assumes a 30-year retirement, which may not be long enough for someone retiring at 40. And it does not account for variable spending patterns — most retirees spend more in the early active years and less as they age.
For Australian FIRE planners, additional considerations include the favourable tax treatment of franking credits, the impact of superannuation (which cannot be accessed until preservation age), and the potential for a part Age Pension later in life. Some Australian FIRE planners use a 3.5% withdrawal rate for added conservatism, while others argue that the combination of super access at 60 and potential Age Pension at 67 makes 4% reasonable or even conservative.
Australian-specific considerations
The super gap
If you plan to retire before age 60, you will have a period where your superannuation is inaccessible. During this gap, you need to fund your living expenses entirely from non-super assets. This is one of the most important considerations for Australian FIRE planning and requires careful modelling to ensure you do not run out of accessible funds before your super becomes available.
Our FIRE projections handle this automatically, modelling your non-super and super assets separately and showing you how they interact over your lifetime.
Medicare and private health insurance
Australia's Medicare system provides a baseline level of healthcare, but many retirees choose to maintain private health insurance for shorter wait times and broader coverage. The Medicare levy (2% of taxable income) and the Medicare levy surcharge (1% to 1.5% for higher earners without private hospital cover) should be factored into your tax planning. In early retirement, if your taxable income drops below the surcharge threshold, you may save on this cost.
Tax optimisation
In early retirement, your taxable income may be significantly lower than during your working years. This creates opportunities for tax-efficient strategies such as realising capital gains in low-income years, making non-concessional super contributions, or structuring income to maximise the use of the tax-free threshold ($18,200) and lower tax brackets. Franking credits from Australian shares can also offset or eliminate your tax liability. Our expense categories feature helps you understand your spending patterns and identify areas where you can optimise.
Building a FIRE plan
A practical FIRE plan involves several key steps. First, calculate your current annual expenses and determine which FIRE variant aligns with your goals. Second, calculate your FI number using your chosen withdrawal rate. Third, assess your current investable assets (both inside and outside super) and your savings rate. Fourth, project forward to estimate when you will reach your FI number.
The FIRE calculator automates this process, letting you input your income, expenses, and current assets to generate a personalised timeline. You can adjust assumptions like investment returns, inflation, and income growth to see how sensitive your plan is to different conditions.
Common mistakes
The most common mistake in FIRE planning is underestimating expenses. People often calculate their FI number based on their current spending without accounting for future costs such as children's education, home maintenance, healthcare, or lifestyle changes. It is better to overestimate your expenses and reach FI with a buffer than to underestimate and find yourself short.
Another frequent error is ignoring inflation. A dollar today will not buy the same goods in 20 years. All projections should be modelled in real (inflation-adjusted) terms, or your FI number will be too low.
Overconcentration in a single asset class — particularly property — is also a risk. Diversification across shares, super, property, and fixed income provides more stable returns and reduces the impact of any single market downturn on your portfolio.
Finally, neglecting the non-financial aspects of early retirement can lead to dissatisfaction. Having a plan for how you will spend your time — whether through volunteering, creative pursuits, part-time work, or travel — is just as important as having the financial resources. FIRE is not just about the numbers; it is about designing a life that is fulfilling and sustainable.