👶 Parents' Details
👤 Parent A (Paying Parent)
👤 Parent B (Receiving Parent)
📋 Step-by-Step Formula Breakdown
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Child Support in Australia 2025: How the Formula Works
Australia's child support system is administered by Services Australia and uses a standardised formula to calculate payments. The formula aims to ensure both parents contribute proportionally to the cost of raising their children based on their incomes and the time they spend caring for the child.
The 8-Step Child Support Formula
Services Australia uses the following steps to calculate child support:
- Child support income: Subtract the self-support amount ($29,043 in 2025-26) from each parent's adjusted taxable income
- Combined child support income: Add both parents' child support incomes together
- Income percentage: Calculate each parent's share of the combined income
- Costs of children: Look up the costs of children from the Ministerial table based on combined income and number/age of children
- Each parent's costs: Multiply costs of children by each parent's income percentage
- Care percentage: Determine each parent's care percentage (nights per year / 365)
- Cost offset: Apply the cost offset table based on care percentage
- Child support payable: Subtract the lower parent's offset from the higher parent's obligation
2025–26 Key Figures
| Parameter | 2025–26 Amount |
|---|---|
| Self-support amount | $29,043 |
| Minimum annual rate | $1,046 |
| Fixed annual rate (high-income payer) | $1,677 |
| Annualised MTAWE (used in costs table) | $92,028 |
Care Percentage and Cost Offsets
| Care Level | Nights/Year | Cost Offset |
|---|---|---|
| Regular care (below 14%) | 0–51 | 0% |
| Regular care (14–34%) | 52–127 | 24% |
| Primary care | 128–175 | 25% + 2% per extra % |
| Shared care (48–52%) | 175–189 | 50% |
| Primary care (53–65%) | 190–237 | 54% + 2% per extra % |
| Majority care (66–86%) | 238–313 | 76% |
| Full care (87%+) | 314–365 | 100% |
How to Manage Child Support in Australia
1. Private Collection
Parents can agree to manage child support privately without Services Australia involvement. This is the simplest option and gives both parents flexibility. A limited or binding child support agreement can be registered with Services Australia to make it legally enforceable.
2. Collect from Child Support
Services Australia can collect and transfer payments on your behalf. This is free and includes enforcement powers if a paying parent defaults — including garnishing wages and tax refunds.
3. Departures and Special Circumstances
Either parent can apply for a change of assessment if the standard formula doesn't reflect their actual circumstances. Grounds include: high costs of caring for a child, significant changes in income, costs of supporting other children, or a parent's failure to reduce their income.
Important: This calculator uses the standard Formula 1 (basic formula for single case assessments). More complex situations — including multiple families, overseas income, salary packaging, or trusts — may produce different results. Always verify your assessment through Services Australia's official estimator at servicesaustralia.gov.au or seek legal advice.
This calculator provides estimates based on the published 2025-26 Services Australia formula. Actual assessments depend on individual circumstances and are determined by Services Australia. This is not legal or financial advice. Contact Services Australia on 131 272 or visit servicesaustralia.gov.au for your official assessment.