Know the number.
Deterministic Australian financial calculators. Official rules, exact arithmetic, full working.
Rules cited from
Australian Taxation OfficeRevenue NSWQueensland Revenue OfficeState Revenue Office TasmaniaReserve Bank of AustraliaInterface preview
Built like an instrument, not a brochure.
Versioned rule packs
Every statutory rate and threshold lives in a hash-verified pack citing its official source. Nothing is hard-coded from memory.
Deterministic engines
Pure functions over exact integer-cent arithmetic. The same inputs produce the same result, every time, on your device.
Fail-closed by design
If a verified rule set cannot be loaded, the calculator says so. It never substitutes a guess, a stale year or a plausible number.
Every result shows its working
Formulas, intermediate values, assumptions, sources and limitations render beside every figure, not behind a support ticket.
Private by default
Calculations run client-side. Scenarios save to your browser. No accounts, no ads.
What this is
PaymentCalcs is a set of deterministic calculators for Australian money decisions: income tax and take-home pay by financial year, PAYG withholding by pay frequency, stamp duty for every state and territory, mortgage and loan schedules run as full period-by-period ledgers, savings projections and GST arithmetic. Every statutory rate and threshold comes from a versioned rule pack citing the official document it was taken from, never from memory and never from a model.
Calculations run in your browser over exact integer-cent arithmetic. If a verified rule set cannot be loaded for the year and jurisdiction you choose, the calculator stops and says so. Results are general information, not financial advice; each one names its assumptions and limitations beside the number, with the method documented on a per-calculator methodology page.