Child Support Australia 2026: How Much?

Australia uses an income-shares model. Both parents' incomes are considered, not just the payer's. The formula looks at: each parent's adjusted taxable income, a self-support amount ($29,043 in 2025-26), combined child support income, the cost of children based on that combined income, and each parent's share of care.

In simple terms: the higher earner pays more, and the parent with less care time pays the other parent to help cover the children's costs.

The formula ensures that children benefit from both parents' incomes in proportion to their capacity. It's not a punishment — it's designed to keep children at roughly the same standard of living they'd have if both parents were together.

Before anything else, each parent gets a self-support deduction of $29,043 (updated annually, roughly one-third of male average weekly earnings). This is the amount the government considers necessary for basic living costs.

Your child support income = adjusted taxable income minus the self-support amount. If you earn $80,000, your child support income is $50,957. If the other parent earns $50,000, theirs is $20,957. Your combined child support income is $71,914.

Your income percentage = $50,957 / $71,914 = 70.9%. The other parent's is 29.1%. This percentage determines your share of the children's costs.

The percentage of time each parent cares for the children directly affects how much child support is payable. There are five care tiers:

Below 14% (0-51 nights/year): No cost offset. You pay your full income share of the children's costs.

14-34% (52-127 nights): You receive a 24% cost offset, reducing what you owe.

35-47% (128-175 nights): Graduated offset from 25% upward, rising by 2% per percentage point above 35%.

48-52% (shared care): Both parents' cost percentages are adjusted. The higher earner still pays something, but it's significantly reduced.

53-100% (majority care): You're the receiving parent. The other parent pays you.

Adjusted taxable income (ATI) is broader than what's on your tax return. It includes: taxable income, reportable fringe benefits (grossed up), total net investment losses (including negative gearing), reportable super contributions (employer contributions above the SG rate plus salary sacrifice), and any tax-free government pensions.

This is designed to prevent income manipulation. You can't just salary sacrifice everything or negative gear your way to a lower child support assessment. The formula sees through most common strategies.

If your income changes significantly (job loss, new job, business downturn), you can apply for a change of assessment to use estimated current income instead of last year's tax return.

The minimum child support assessment is approximately $500 per year (around $19.23/fortnight or $9.62/week). This applies when a parent's income is below the self-support amount or in other limited-income situations.

There's also a fixed assessment for parents on income support payments, and special rules for high-income earners (income above 2.5 times the average weekly earnings).

Child support can be collected by Services Australia (through tax office deductions from wages) or paid directly between parents through a private agreement. Private agreements offer more flexibility but less enforcement protection.