Child Support in Australia — How It's Calculated

Services Australia calculates child support based on both parents' incomes, the number of children, and the care arrangement.

Last updated April 2026 · Source: Services Australia · Financial year: 2025–26 Current 2025–26
The Answer
Based on both parents' incomes
Assessed by Services Australia. The formula considers each parent's taxable income minus a self-support amount, the number of children, their ages, and the percentage of care each parent provides.

How It's Calculated

The child support formula considers:

  1. Each parent's adjusted taxable income
  2. Minus a self-support amount (~$28,000 each)
  3. Combined child support income
  4. The costs of the children (from the Costs of Children Table — based on income and number/age of children)
  5. Each parent's percentage of care (nights per year)
  6. The higher earner pays the difference

Example

Parent A earns $90,000. Parent B earns $50,000. Two children. Parent A has 35% care (128 nights), Parent B has 65% care (237 nights). The formula calculates that Parent A pays approximately $10,000–$14,000/year to Parent B.

Collection Methods

MethodDetail
Private collectionParents arrange payment directly between themselves
Services Australia collectionDeducted from the paying parent's wages or Centrelink payment

Changing Your Assessment

If your income changes significantly (lost your job, got a raise), you can apply to have your child support reassessed. Contact Services Australia Child Support on 131 272.

Frequently Asked Questions

How much child support will I pay?

It depends on both parents' incomes, the number of children, and the care arrangement. Use the Services Australia Child Support Estimator at servicesaustralia.gov.au for an estimate.

What if the other parent won't pay?

If they're supposed to pay through Services Australia collection, the agency can deduct it from their wages, tax refund, or Centrelink payments. If it's a private arrangement, you can switch to agency collection.

What Changed

Apr 2026 Content verified
Last updated: April 2026 · Source: Services Australia · Financial year: 2025–26