For a second earner in a couple family, an extra day of work isn't the gross day-rate: it's taxed at your marginal rate, lifts combined family income (withdrawing Family Tax Benefit Part A), and steps your Child Care Subsidy down so the same care costs more. See the per-day gross beside the net, with each reduction cited to its source.
Educational tool. Not financial advice.
Your partner's annual income
The other earner in the couple — their income is fixed across the scenario.
$
Your income before the extra days
What you already earn — the modelled days stack on top of this.
$
Gross pay for one extra day
Your gross pay for a single additional day of work.
$
How many extra days to model?
5 days
Do you have a child in subsidised care?
Yes — include the Child Care Subsidy step-down for one child.
Do you have a HELP / study loan?
Yes — an extra day can also lift my compulsory study-loan repayment.