📅 Age Pension rates: $29,754/yr single · $44,856/yr couple (FY 2025-26, full pension) · Eligibility age: 67 · Subject to assets and income tests.
How to calculate your FIRE number
The FIRE number formula is deceptively simple: FIRE number = Annual expenses ÷ Safe withdrawal rate. At the standard 4% SWR this is also written as Annual expenses × 25.
The intuition: if your portfolio earns a real return (above inflation) of 4% per year, you can withdraw 4% indefinitely without depleting the principal. In practice, the Trinity Study showed this works in 95% of historical 30-year scenarios using US market data — Australian research produces similar findings.
For Australians retiring in their 40s or 50s, the retirement horizon is 40–50+ years, making a lower SWR (3.5%) more prudent. The Age Pension toggling in this calculator is a significant feature: if you plan to receive the Age Pension from 67, your portfolio only needs to cover the gap between your expenses and the pension amount, dramatically reducing your FIRE target.
Frequently asked questions — FIRE number
What is a FIRE number?
Your FIRE number is the total investment portfolio size required to sustain your lifestyle indefinitely through investment returns alone. It is calculated by dividing your annual expenses by your chosen safe withdrawal rate (SWR). At the standard 4% SWR, the formula is simply: Annual expenses × 25. For example, $60,000/yr in expenses × 25 = $1,500,000 FIRE number.
What is the 4% rule and does it apply in Australia?
The 4% rule comes from the 1998 Trinity Study, which analysed US stock and bond market data from 1926–1995. It found a diversified 50/50 portfolio could sustain 4% annual withdrawals for 30 years in 95% of scenarios. Australian research using local market data shows similar results. For longer FIRE horizons (40–50+ years), 3.5% is considered more conservative and appropriate.
How does the Age Pension affect my FIRE number?
From age 67, eligible Australians receive the Age Pension (up to $29,754/yr single, $44,856/yr couple combined, FY 2025-26). This directly offsets how much you need to draw from your portfolio, effectively reducing your required FIRE number. A single person spending $60,000/yr only needs the portfolio to cover $30,246 — a FIRE number of $756,000 instead of $1,500,000. The Age Pension is means-tested so use it as a conservative bonus rather than a certainty.
Which safe withdrawal rate should I choose?
3% = very conservative, for 50+ year retirements or low risk tolerance. 3.5% = conservative, for 40–50 year FIRE retirements (retiring in your 40s). 4% = standard, supported by the Trinity Study for 30-year retirements. 4.5–5% = more aggressive, suitable only if you have flexibility to reduce spending in down markets or plan to return to some paid work. Most Australians retiring early choose 3.5%.
Does the FIRE number include my super?
This calculator shows the total portfolio needed, regardless of where the money sits. However, superannuation is locked until age 60 (preservation age for those born after 1 July 1964), which means your FIRE plan needs a 'bridge fund' of non-super investments to cover expenses between your FIRE age and age 60. The FIRE Timeline Calculator models this two-part structure explicitly.