Working backwards from take-home pay to the salary behind it is not a matter of adding a percentage, because the rate scale is progressive.
Two different calculations share the name “gross up”, so they are separate modes here rather than blended into one answer.
Converts an after-tax amount back to the taxable income that produces it, using the statutory rate scale — or grosses up a non-taxable amount by a factor you set.
Which set applies depends on the jurisdiction and the date you enter. Sources last checked 2026-08-30.
Commonwealth — Income tax
1 July 2024 to 30 June 2026
Income Tax Rates Act 1986 (Cth), Schedule 7 Part I — Resident taxpayers
Commonwealth — Income tax
1 July 2026 to 30 June 2027
Income Tax Rates Act 1986 (Cth), Schedule 7 Part I — Resident taxpayers
Commonwealth — Income tax
1 July 2027 onwards
Income Tax Rates Act 1986 (Cth), Schedule 7 Part I — Resident taxpayers
Commonwealth — Medicare levy
1 July 2026 onwards
What you are converting
Inverting tax answers “what salary leaves this in my account”. A stated factor answers “what is this untaxed payment worth in pre-tax terms”. They are not the same question and do not share a method.
Gross-up factor
Used only in factor mode. The multipliers applied to non-taxable income in lending are individual lenders’ credit policy rather than a published rule, so none is supplied.
Income year
Which year’s rate scale to invert. Legislated changes mean a future year can differ from this one, so the year has to be stated.
The headline in tax mode is the taxable income required. The check line below it recomputes the after-tax figure at that gross, and it should match what you entered — that is the answer proving itself.
The gap between the average rate and the marginal rate explains why a percentage cannot do this job. Adding thirty per cent to a net figure gives the wrong answer at every income, and the size of the error grows with the income.
In factor mode nothing is inferred about tax at all. The tax line reads zero because the mode assumes the amount is not taxed, which is the whole reason for using a factor.
Every figure below is computed by the same calculator on this page, from the inputs described. Nothing here is typed in by hand, so an example cannot disagree with the tool.
Compare the average rate against the marginal rate. Applying the marginal rate to the net figure would overshoot the gross badly, which is why this is bisected rather than multiplied.
Nothing about tax is asserted here. The result is the amount multiplied by the factor you chose, and its usefulness depends entirely on whether that factor is the one your lender applies.
Tax plus the Medicare levy is strictly increasing in income, so exactly one taxable income leaves any given after-tax amount. The calculator narrows an interval containing it by repeated halving, a fixed number of times.
A single formula would be neater but does not exist: the Medicare levy shade-in creates a bend that does not line up with the tax brackets, so the combined function has kinks the brackets alone do not predict.
How every calculator on this site is built · Regulatory sources
A resident individual
The scale inverted is the resident scale with the Medicare levy, no spouse and no dependants. Foreign residents and working holiday makers are taxed differently and are not modelled.
No offsets
Offsets, the levy surcharge and study loan repayments all change what actually lands in an account. The gross reported is the one implied by the scale, not by your return.
Salary packaging is not modelled
Amounts sacrificed before tax change the relationship between gross and net in ways a single scale inversion cannot capture.
No lender factor is endorsed
A factor is offered as an input, not a recommendation. Which figure a lender applies to which payment is its own policy.
Works out income tax and the Medicare levy on a resident individual’s taxable income, using the statutory rate scale for the income year you choose.
Converts pay quoted hourly, weekly, fortnightly, monthly or quarterly to a yearly figure.
Solves for the loan a set of assumptions you control will support — income, declared expenses, commitments, an assessment buffer and a surplus you want to keep.
This calculator can be embedded on a business website, branded to match it, with a call to action that sends the enquiry to that business rather than collecting anything here.