BestMate Calculators is a small, independent collection of free web tools built for the moments where a rough estimate — done properly — beats a guess. No accounts, no paywalls, no data harvesting. Just the calculator, and an honest explanation of how it got its answer.
Most "calculator" tools online exist to capture your email address before showing you a number, or to nudge you toward a paid product partway through. We wanted the opposite: open the page, enter your numbers, get an answer, and see exactly how that answer was worked out — down to the tax brackets and multipliers used.
The first tool, the Cost of Living Explorer, came out of a simple frustration: it's genuinely hard to tell, before you move, whether a salary that sounds fine in one city will actually stretch to cover rent in a specific suburb of another. Most relocation content is either a listicle or a sales pitch. We wanted a dashboard instead.
BestMate Calculators is built and maintained by a solo, Melbourne-based developer — not a registered financial services company, a media outlet, or a comparison network with an affiliate deal behind every recommendation. It started as a way to answer one genuine personal question (see above) and grew one calculator at a time from there. There's no editorial desk or call centre behind this site: one person builds the tools, checks the numbers, and fixes what's wrong when it's reported.
Each tool answers one specific, common money question well, rather than trying to be an all-in-one financial planner:
They're built for a quick, well-informed estimate before a bigger decision — not as a replacement for a broker, accountant, or financial adviser once you're ready to act.
Every number on this site comes from a plain, published formula running in your own browser — there's no black-box model, no AI estimate, and no server-side "secret sauce." Income tax is calculated using the real marginal-bracket method the ATO uses (each bracket only taxes the slice of income within it). Mortgage repayments use the standard reducing-balance principal & interest formula lenders use. Rent and cost-of-living figures scale a published city-level median by a suburb-tier multiplier. Each calculator's own "Methodology & assumptions" panel shows the exact formula and figures used for that tool.
Practically, that also means every calculator is static and client-side (the maths runs entirely in your browser; your calculator inputs are never sent to or stored on any server we operate — see the Privacy Policy for what analytics/advertising tools separately collect, with your consent), and free, indefinitely — no premium tier, no locked results, no "unlock full answer" paywall.
Figures are drawn from publicly available Australian data, not invented or scraped from unnamed sources:
Each calculator's "Sources & further reading" panel links to the specific sources most relevant to that tool.
Different figures move on different schedules, so they're updated differently:
Between updates, treat market-based figures (rent, property prices) as a snapshot in time, not a live feed — see each tool's own page for exactly how current its numbers are.
To keep formulas understandable rather than turning every calculator into a 40-field form, each tool makes deliberate simplifying assumptions — common ones include Australian tax residency, no HECS/HELP debt, no salary packaging or offsets, and a constant interest rate for the life of a loan. These aren't hidden: every calculator's own "Methodology & assumptions" panel spells out exactly which simplifications apply to that specific tool, so you can judge how much they matter for your situation.
These are estimates, not guarantees. Every figure on this site is a well-informed estimate built from published benchmarks and standard formulas — not a live data feed, a personalised assessment, or a substitute for a mortgage broker, accountant, tax agent, or financial adviser. Real outcomes depend on details these tools don't (and can't) know about your specific situation. Treat every output as a solid starting point for your own research, not a final answer.
There's no formal editorial board behind a solo project like this one, but figures aren't just typed in and shipped either. Before a formula goes live, it's tested against independently published reference values (for example, checking the mortgage formula reproduces a textbook repayment figure, or confirming a tax-cut example matches numbers reported elsewhere) rather than trusted on faith. When an error is found — whether through that process or a report from someone using the site — it's corrected directly in the code, and the fix ships as soon as it's verified. If you spot something that looks wrong, that report is genuinely useful — see below.
Found a bug, spotted an outdated figure, or want to suggest the next calculator? We'd genuinely like to hear it — head to the Contact page.