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A bonus generally adds to your other salary income. This tool compares the annual tax position before and after the bonus, so it captures the tax slices and HELP changes that a flat percentage can miss.
There is no separate flat bonus tax rate
A bonus can look heavily taxed on the payslip because payroll withholding rules deal with an irregular payment. Your final income tax still depends on annual taxable income and the deductions and offsets you can claim.
The calculator adds the bonus to your salary, works out the annual deductions again, then shows the difference in take-home pay. It assumes the bonus is cash salary and excludes any separate employer super paid on it.
The bonus can change more than income tax
HELP repayment income rises with a taxable bonus. The Medicare levy surcharge may also change if your income crosses a tier and you do not have the required hospital cover.
If you have eligible hospital cover for only part of the year, the actual surcharge depends on the uncovered days. This calculator models a full year with or without cover.
Use the annual estimate to plan, not to forecast payroll
A bonus paid early in the year, a changed tax declaration or an employer’s withholding approach can affect the amount received on the day. The annual comparison is useful for the final overall cost.
If your base salary changed during the year, use your expected total salary for that year instead of simply multiplying the newest monthly pay by 12.
Common questions
Why is my bonus payslip different from this result?
The result compares annual tax positions. Payroll uses withholding rules for the actual payment and timing. The tax return reconciles the final income tax position.
Sources you can check
Sources checked for this page on 2 October 2026. Statistics keep their own measurement dates.