Australia: marginal rates, the Medicare levy and super
Australia keeps the headline structure simple: one national scale, no state income tax, no separate social-insurance contributions. For 2026-27 the rates are nil to $18,200, then 15% (down from 16%) to $45,000, 30% to $135,000, 37% to $190,000 and 45% above.
What complicates an Australian payslip is everything bolted on around the scale. The Medicare levy adds 2%, but it does not start abruptly: below $28,011 of taxable income nothing is charged, and between there and $35,013 it phases in at 10c per dollar of the excess. The low income tax offset takes up to $700 off the tax due, tapering by 5c per dollar from $37,500 and then by 1.5c from $45,000 until it runs out at $66,667. It is not refundable, so it can reduce your tax to zero but never below it.
Two more items catch people out. If you have no private hospital cover and earn above $105,000, the Medicare levy surcharge adds 1% to 1.5% charged on your whole income rather than only the part above the threshold, which is why a basic policy is often cheaper than the surcharge. And a HELP or HECS debt triggers a compulsory repayment once income passes $69,528, at 15% of the amount above that and 17% higher up, reverting to a flat 10% of total income above $186,050.
Superannuation is not a deduction. The 12% guarantee is paid by your employer on top of your salary, so it never reduces take-home pay. It only matters here when a job is advertised as a package "including super", in which case the salary actually taxed is the package divided by 1.12. The calculator has a switch for exactly that, and always shows super separately as an employer cost.
Worked example: $90,000, resident with private cover, 2026-27
Income tax: nil on the first $18,200; 15% on $26,800 = $4,020; 30% on $45,000 = $13,500. Total
$17,520. The low income tax offset has run out by $66,667, so none applies.
Medicare levy: 2% of $90,000 = $1,800. No surcharge, because of the hospital cover.
Take-home: $90,000 − $17,520 − $1,800 = $70,680 a year, $5,890 a month.
Superannuation of $10,800 is paid on top, making the total cost of employment $100,800.