Methodology - Australia (2025-26)

Educational model - not ATO PAYG withholding tables, not a notice of assessment, not tax advice.

Employee (PAYG)

Resident income tax 2025-26: nil to $18,200, 16% to $45,000, 30% to $135,000, 37% to $190,000, 45% above.
Medicare levy: 2% of taxable income, with a low-income reduction (single: no levy to $27,222, shaded in at 10c per $1 to $34,027, full 2% above).
Low Income Tax Offset (LITO): up to $700 at or under $37,500; minus 5c per $1 to $45,000 (down to $325); minus 1.5c per $1 to $66,667 (down to $0). It reduces income tax only, not the Medicare levy.
Superannuation Guarantee 12% (from 1 July 2025) is shown as an employer cost on top of salary, not deducted from gross pay.
Australia has no state or territory income tax, so there is no state selector.
Out of scope: Medicare levy surcharge, private health rebate, HELP/HECS-HELP and other study loans, work-related deductions, salary sacrifice, the maximum super contribution base, non-resident and working-holiday-maker rates, and offsets other than LITO.

Net business income = revenue - expenses, taxed at the same resident rates as an employee, plus the Medicare levy and LITO.
No Superannuation Guarantee to yourself (super is voluntary) and no PAYG withholding from a salary; PAYG instalments are paid through the year instead.
Out of scope: GST (registration required once turnover reaches $75,000), the small business income tax offset, depreciation and the instant asset write-off, instalment timing, Medicare levy surcharge, HELP/HECS and non-resident rates.