Child Support Formula Australia 2026
How does Services Australia calculate child support? Why does your payment change when income or care arrangements change? The answer lies in the 8-step formula that determines every Australian child support assessment.
Do Both Parents Pay Child Support?
This guide explains the Australian child support formula in plain English. You'll learn how income and care percentages affect payments, what the Self-Support Amount means, and see real examples showing exactly how the calculation works.
The Australian child support formula (Formula 1) calculates payments by comparing each parent's income share against their care share. It involves 8 steps: calculate child support income (taxable income minus $31,046), determine combined income, calculate income percentages, look up costs from official tables, convert care to cost percentages, then apply: (Income % - Cost %) × Total Costs. This ensures fair payments based on capacity to pay and direct care contribution.
How Income Affects Child Support
Services Australia uses this 8-step formula to calculate child support. Each step builds on the previous one to determine the final payment amount.
A common misconception is that child support is a one-way street. In reality, the formula assesses both
How Care Percentage Affects Payments
Your income determines two things: your income percentage (share of costs) and the total costs of children (higher combined income = higher costs from the table). If you're router.push('/blog/child-support-self-employed')} > self-employed
Care percentage converts to cost percentage using a formula. More care = higher cost percentage = lower child support payments. See the complete router.push('/blog/child-support-care-percentage-table')} > care percentage table
How Much Child Support with 50/50 Custody?
With 50/50 custody (equal care), the parent with higher income typically pays child support to the other parent, but the amount is significantly lower than sole-care arrangements. Example: Parent A earns $80,000, Parent B earns $50,000, 50/50 care → Parent A pays approximately $4,200/year ($350/month) for 1 child. The formula recognizes both parents are directly covering costs when children are in their care. This is a 69% reduction compared to 0% care scenarios.
The formula is complex, but our calculator handles all the math for you. Enter your details and get an instant, accurate estimate.
Frequently Asked Questions
Understanding the Formula
Frequently Asked Questions
What is the child support formula in Australia?
The Australian child support formula is an 8-step calculation that considers both parents' incomes, the cost of raising children (based on age and number), care percentages, and any relevant dependents. The formula determines each parent's income share and cost share, then calculates who pays whom based on the difference.
How does income affect child support in Australia?
Your Adjusted Taxable Income (ATI) determines your share of child support costs. After deducting the Self-Support Amount ($31,046 in 2026), your remaining income is compared to the other parent's to calculate your income percentage. Higher income means a higher percentage of costs you're expected to cover.
How does care percentage affect child support?
Care percentage determines your cost percentage—how much of the child's costs you're expected to cover through direct care. More care means lower child support payments. At 50/50 care, payments depend entirely on income difference. Below 14% care, you get no cost offset.
What is the Self-Support Amount in child support?
The Self-Support Amount (SSA) is the minimum income each parent needs to support themselves. In 2026, it's $31,046 per year. This amount is deducted from each parent's income before calculating child support, ensuring parents can meet their own basic needs.
What is the Self-Support Amount in child support?
The Self-Support Amount (SSA) is the minimum income each parent needs to support themselves. In 2026, it's $31,046 per year. This amount is deducted from each parent's income before calculating child support, ensuring parents can meet their own basic needs.
Do both parents have to pay child support?
Technically, both parents are assessed for the cost of the child based on their income. These amounts are then offset against each other and the care they provide. Usually, this results in a single strict payment from one parent to the other, but the calculation involves contributions from both.
Calculate Your Child Support
Use our free 2026 calculator to get an instant, accurate estimate based on the official Services Australia formula.
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