Calculate ATI: Enter the Adjusted Taxable Income for both parents. This is usually your gross income plus any fringe benefits or super contributions, minus the Self-Support Amount (automatically deducted here).
Add Children: Input the number of children you share with the other parent, separated by age groups (Under 13 and 13-17). Older children have a slightly higher assessed cost.
Set Care Percentage: Use the slider to estimate how many nights per year the children sleep at your house. This determines your "Cost Percentage."
Review the Estimate: The calculator applies the Services Australia 8-step formula to estimate who pays whom, based on the gap between your Income Share and your Care Share.
Frequently Asked Questions
What counts as Adjusted Taxable Income (ATI)?▼
ATI is not just your take-home pay. It includes your taxable income plus reportable fringe benefits, target foreign income, total net investment losses, and reportable superannuation contributions.
How does care percentage affect child support?▼
Services Australia uses specific thresholds. For example, having care for less than 14% of nights (approx 52 nights) results in a 0% Cost Percentage. Reaching 35% care (Regular Care) or 48-52% care (Shared Care) significantly changes the assessment formula.
Is this calculator legally binding?▼
No. This tool provides an estimate based on the standard 8-step formula. The actual amount payable is determined by the Child Support Registrar (Services Australia) after a formal assessment application is lodged.
What is the Self-Support Amount?▼
The Self-Support Amount represents the money a parent needs to support themselves before child support is calculated. For 2024/2025, this is approximately $29,484. It is deducted from your ATI to determine your Child Support Income.