How we check our figures

A projection is only as good as the rules in it. My Runway applies Australia’s tax, super, stamp duty, land tax and Age Pension rules to your figures, every year. This is how we make sure it applies them as the law and the agencies that run it publish them.

Every rate from its official source

Tax brackets, levies, super caps, duty scales, land tax thresholds and pension rates come from the body that sets them: the ATO, Services Australia, the Department of Social Services, each state and territory revenue office, and the Acts themselves. Each rate is stored with the page it came from and the day it was checked. The current tables were checked against those sources in September 2026.

Tested against published examples

Where the ATO or a revenue office publishes a worked example, the app has to reproduce it to the cent. Where none is published, the case is worked by hand from the published scale. These checks run on every change to the app, and a change that breaks one can’t be released.

Compared with the official calculators

We run the rules over ranges of incomes, prices and balances against the calculators the ATO, every state revenue office, Services Australia and MoneySmart publish: income tax and levies, HELP repayments, super, capital gains tax, stamp duty in every state and territory, land tax, home loan repayments and the Age Pension. Every difference is either fixed or explained, with a source, such as another calculator still using last year’s rates. No official calculator applies the capital gains changes from 1 July 2027 yet, so those are checked against the worked examples published with the law, and cases worked by hand from the Act.

Worked out a second way

A set of example households, between them using every option the app has, is also worked out by a separate model written from the law and our documentation, without the app’s own code. Every figure in every year has to agree to the cent, and so does the year each milestone lands in.

Every dollar accounted for

Over long projections and hundreds of randomly generated households, the app checks that money is never created or lost: what every account, loan and property holds at the end of a year is what it held at the start, plus and minus that year’s flows, to the cent.

When a rule changes

Most rates change each July, and some in March and September. When one does, the new figure goes in with its source and the day it was checked, and the tests that read it are run again. Any figure that moves as a result is named and explained before the change is released.

What checking can’t cover

• Your figures and assumptions. Growth, returns, inflation and pay rises can’t be looked up. The app starts from defaults it shows you, and every one is yours to change.
• Estimates. Lenders mortgage insurance and purchase fees aren’t published by any government, so they are estimated from typical figures, and you can type in your own.
• Years ahead. Past the last published rates, the latest table carries forward, with thresholds grown the way the law indexes them.
• Rules not yet in the app. Where the numbers come from lists the rules My Runway applies today.

My Runway is a calculator: it shows what the rules do to the figures you give it, and gives general information, not financial advice. Check the figures that matter to you with their source.

Found a figure that looks wrong?

Please tell us at [email protected], with the year and the figure. We check it against the source and reply.