About CheckTax

CheckTax is a set of free Australian tax calculators built and verified by J. Tinjak, an operations administrator in Brisbane’s grocery cold chain, and an aspiring business analyst. Not a CPA, not a registered tax agent, and not pretending to be either. Every figure on every calculator is traced to its primary source: the ATO for federal taxes and superannuation, and the relevant state revenue office for stamp duty and land tax. The verification trail lives at /methodology/.

Why this site exists

I got tired of plugging numbers into other Australian tax calculators and being shown a single big figure with no working, no source, and a copyright date on the page from three years ago. Most calculators on the first page of Google have at least one of these problems: rates that haven’t been updated, no link to where the rate came from, no working shown, or a “sign up to see your full result” wall. CheckTax is the calculator I wanted to use and couldn’t find. Every figure is dated, linked to its source, and shows the Act or ATO ruling it came from.

Who I am, plainly

I work in operations administration for one of the big Australian grocery cold-chain businesses. Day to day I deal with purchase invoicing, transport billing for ad-hoc loads, and consumables tracking; I’m currently being trained to cover the business analyst role while ours is away. I applied for the BA role previously and have used the time since to deliberately build my depth in finance, tax and analysis. CheckTax is part of that: building these calculators is how I make myself sit with the legislation, the ATO QC pages and the state Duties Acts long enough to actually understand them.

I’m not a CPA, CA, CFP or registered tax agent. I will never claim to be. The advantage of saying that out loud is that I have no incentive to oversimplify, dress up a guess, or sell you anything you don’t need. I make mistakes; when one is pointed out, I fix it in public and the fix lands on the changelog.

How CheckTax is funded

Today CheckTax is free, has no signup, no paywall, and no upsell. Maintaining 13 calculators against rules that move every Budget is real work, and at some point that work has to be funded in a way that fits the audience rather than fights it. Over time that’s likely to mean a mix of unobtrusive third-party advertising and affiliate or partner links to Australian providers in adjacent areas: tax software (lodgement, BAS, payroll), mortgage brokers next to the stamp duty tool, conveyancers, accountants, and money tools, where the product is a genuine match for the person already reading the page. Anything commercial that appears here will be relevant, won’t hide the calculator or the working, and will be marked plainly on the page where it shows up.

The hard rule is that money does not bend the numbers. The calculators run the same code, cite the same primary sources, and call out the same scope limits regardless of who is paying. A sponsor cannot dictate which way a figure rounds, and a partner cannot buy a recommendation; if a tool isn’t right for the visitor it doesn’t get a link, full stop. Anything that involves a payment to CheckTax is disclosed on the page where it appears, on the Disclaimer page, and on the Privacy page.

If you run a product in Australian tax, property, accounting, payroll or money tools and you think a partnership makes sense, email [email protected] with a one-paragraph pitch and a link. Sponsorship, affiliate or display-ad enquiries are welcome via the same address. No template outreach, no SEO link swaps, no paid content dressed up as editorial; the site doesn’t take any of that.

How the numbers stay accurate

• Rates come straight from the ATO for income tax, GST, HECS and superannuation, and from the relevant state revenue office for stamp duty and land tax. No third-party calculators in the chain.
• Every figure is checked against its source before it goes live, not recalled from memory and not copied from competitors. The verification skill that drives this is documented in the repo as a non-negotiable rule.
• Where a model is deliberately simplified (for example, the single Medicare levy threshold or the omission of pre-1993 leave components on the termination-pay calculator), it’s called out on the calculator page and on the methodology page rather than buried.
• Prose is hand-written and reviewed. No template paragraphs, no boilerplate “leverage / delve / seamless” jargon, no bold-label bullets dressed up to look like advice. See the changelog for the most recent prose-and-facts pass.

What this isn’t

CheckTax is not the ATO, not a government tool, not a registered tax agent and not a financial adviser. The calculators give general estimates so you can sanity-check a payslip or plan ahead. They aren’t personal advice. See the Disclaimer.

Corrections and contact

If a figure looks wrong, email [email protected]. Rate issues usually get confirmed against the source the same day. If it’s a real error I’ll fix it, push it, and credit the report on the changelog.