About
MyNextDollar is a free Australian financial modelling platform. We build calculators that help Australians understand the numbers behind financial independence, mortgage strategy, and wealth building — so they can make better decisions without needing to hire an advisor for every question.
Who Builds This
I'm a geologist-turned-builder who got frustrated with financial calculators that hand-wave how Australian tax actually works.
Every projection on MyNextDollar runs on current ATO mechanics for FY2026-27 — Stage-3 brackets, super contribution caps and HELP thresholds.
The calculation engine is covered by 88 unit tests and 10,000 fuzz scenarios, so what you see is exactly what the rules produce — not a rough estimate.
Why We Build
We believe financial decisions should be made with data, not emotion. That means running scenarios. Exploring how small changes compound. Testing assumptions before committing to them. Understanding the gap between what you think will happen and what the numbers show actually happens.
Most people don't have a financial advisor on speed dial for every "what if" question. And most advisors charge you to explore scenarios. We built this platform so anyone can run the numbers themselves — to see what marginal improvements to savings, investment returns, or work patterns actually mean over a decade or two. That's where clarity comes from.
Our Approach
Every calculator on MyNextDollar is built around one principle: show you the actual maths, not a simplified approximation. We model the Australian super system correctly — including the preservation age bridge problem that most FIRE calculators ignore. We model tax at Australian marginal rates. We model windfalls with the correct tax treatment depending on whether they arrive before or after your retirement age.
The tools sync with each other — update your income in the FIRE calculator and it flows through to the mortgage and part-time calculators. Update your super balance and it updates everywhere. This is intentional: your finances are interconnected, and your tools should be too.
Scenario Modelling, Not Financial Advice
MyNextDollar provides scenario modelling tools, not financial advice. The calculators show you what the numbers say given your inputs and assumptions. They do not account for your complete financial situation, risk tolerance, tax position, insurance needs, estate planning, or other factors that a qualified financial adviser would consider.
The outputs are projections based on the assumptions you enter. Future investment returns, inflation, and tax rates are uncertain. Plans involving superannuation, debt, or investment strategy should be reviewed with a licensed professional before implementation.
We don't earn commission on financial products. We don't have affiliate relationships with super funds, brokers, or banks. The tools are free to use and we have no financial incentive to recommend any particular product or strategy.
Methodology
- Tax rates: Australian individual income tax brackets for FY2026-27 (second bracket cut to 15% from 1 July 2026). Super contributions tax at 15%; concessional cap $32,500, non-concessional $130,000. CGT with 50% discount for assets held 12+ months.
- Investment returns: User-configurable. Defaults: 8% ETF nominal, 7% super nominal. No guarantee these returns will be achieved.
- Inflation: User-configurable. Default: 2.5% p.a. — the midpoint of the Reserve Bank of Australia's 2–3% target band, which is the appropriate long-run assumption for multi-decade projections. (Current trimmed-mean inflation is running higher at ~3.4% to April 2026, but the RBA expects it to ease back toward 2.5%.) Projections are expressed in today's dollars (real).
- Super preservation age: Currently 60 for those born after 30 June 1964. Earlier birth years have lower preservation ages.
- Safe withdrawal rate: User-configurable. Default 4% (Trinity Study). Conservative users should consider 3.5% for long retirements.
- Superannuation guarantee: 12% (from 1 July 2025). Applied to salary in the relevant year.
Data and Privacy
All calculator data is stored locally in your browser. We do not store, transmit, or have access to any financial data you enter. Nothing leaves your device unless you explicitly export it. There is no account creation required and no data collection beyond standard anonymous analytics (page views, not financial inputs).