Child support: how it is worked out

We don't estimate child support here. The official formula has rules we can't reproduce reliably in a simple tool, such as multiple cases, relevant dependants, minimum and fixed assessments, and non-parent carers. Use the official Services Australia child support estimator.

Have these ready

• Both parents' adjusted taxable income
• Number and ages of children (0–12 and 13+ are treated differently)
• Nights of care each. Work out the care percentage with our care percentage tool
• Any other children you support

The 8 steps (official)

1. Each parent's income minus the self-support amount (2026: $31,046)
2. Add the two incomes together
3. Each parent's share of that combined income
4. Care percentage
5. Cost percentage (from care)
6. Income % minus cost % = child support %
7. Costs of children, from the 2026 table
8. Positive child support % × costs = amount payable