Data sources & assumptions
How FirePath calculates your number
FirePath uses real Australian data to build your projections. This page shows you exactly what we use, where it comes from, and what we're still working on. No hidden assumptions.
HOW A FREEDOM NUMBER GETS BUILT
An example — sign in to see this built from your own numbers.
Live data — updated daily from official sources
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Fixed assumptions
Investment return
The rate used for your freedom date calculation
The rate used for your freedom date calculation
7% real
after inflation
after inflation
Freedom number method
Based on the Trinity Study 4% safe withdrawal rule
Based on the Trinity Study 4% safe withdrawal rule
25× annual
spending
spending
Super growth rate
Applied to your projected super balance
Applied to your projected super balance
7% nominal
Gross income estimate
Used to calculate employer super contributions
Used to calculate employer super contributions
Net ÷ 0.72
Inflation assumption
Used in nominal projections and inflation toggle
Used in nominal projections and inflation toggle
2.5%
RBA long-run target
RBA long-run target
Projection horizon
Maximum modelled timeline
Maximum modelled timeline
100 years
Tax engine — 2025-26 / 2026-27
FirePath's tax engine auto-switches between financial years on 1 July. All figures sourced directly from the ATO.
Income tax brackets 2025-26
0% / 16% / 30% / 37% / 45% — Stage 3 cuts applied
0% / 16% / 30% / 37% / 45% — Stage 3 cuts applied
Income tax brackets 2026-27
Second bracket drops from 16% to 15% from 1 July 2026
Second bracket drops from 16% to 15% from 1 July 2026
Auto-applied
Medicare levy
2% of taxable income — threshold $27,222 (2025-26)
2% of taxable income — threshold $27,222 (2025-26)
2%
LITO
Low Income Tax Offset — up to $700, phases out at $66,667
Low Income Tax Offset — up to $700, phases out at $66,667
$700 max
Concessional cap 2025-26
Employer SG + salary sacrifice + personal deductible contributions
Employer SG + salary sacrifice + personal deductible contributions
$30,000
Concessional cap 2026-27
AWOTE-indexed increase from 1 July 2026
AWOTE-indexed increase from 1 July 2026
$32,500
Non-concessional cap 2025-26
After-tax contributions
After-tax contributions
$120,000
Super Guarantee rate
12% from 1 July 2025 — permanent, no further increases legislated
12% from 1 July 2025 — permanent, no further increases legislated
12%
Super contributions tax
Concessional contributions taxed inside super
Concessional contributions taxed inside super
15%
Age Pension eligibility age
Services Australia
Services Australia
67
Age Pension — single (max)
As at March 2025 — indexed March and September
As at March 2025 — indexed March and September
$1,200.90/fn
What FirePath models — and what's coming
FirePath is honest about its limits. We'd rather tell you what we're working on than pretend it's already done.
83%
10 of 12 planned modelling features are live. The rest are being built in the open — see below.
Tax inside super (15% contributions tax)✅ Done
Tax-free super withdrawals after age 60✅ Done
Salary sacrifice — tax saving and super gain✅ Done
Income tax modelling (2025-26 and 2026-27 brackets, LITO, Medicare)✅ Done
Offset vs invest comparison✅ Done
Partial FIRE / withdrawal rate modelling✅ Done
Range-based projections (conservative / base / optimistic)✅ Done
Real vs nominal inflation toggle (2.5% RBA target)✅ Done
Age Pension means test and income interactions✅ Done
Longevity modelling — portfolio runway to age 90+✅ Done
Super fees and insurance premiums🔧 Coming soon
Sequence of returns risk🔧 Coming soon
Why we use 7% as the investment return
The 7% real return (after inflation) is the most widely used assumption in financial independence planning — grounded in over a century of market data.
Shiller dataset
150+ years of US equity returns
150+ years of US equity returns
~7% real
MSCI World Index
Long-run global equity average
Long-run global equity average
~7% real
Trinity Study (1998)
Academic basis for the 4% rule
Academic basis for the 4% rule
7% assumed
Vanguard Australia
Long-run Australian equity research
Long-run Australian equity research
~7–8% real
Past returns don't guarantee future results. FirePath uses 7% as a planning assumption, not a prediction.
Official data sources
RBA — Reserve Bank of Australia
Cash rate and CPI inflation data
Cash rate and CPI inflation data
ATO — Australian Taxation Office
Tax brackets, super guarantee rate, contribution caps
Tax brackets, super guarantee rate, contribution caps
Services Australia
Age Pension rates and means test thresholds
Age Pension rates and means test thresholds
MoneySmart — ASIC
Super preservation age, general financial education
Super preservation age, general financial education
FirePath is an educational tool. We don't provide financial advice.
Projections are illustrative only based on your inputs.