How do I calculate Child Support in NSW?

The Child Support Agency uses a mathematical formula to automatically calculate the amount of child support payable.

How does the formula work?

The Formula is based on the income available to a parent. This adjusted taxable income minuses the cost of ‘self support’ and the number of other dependent children the parent is liable to support, to calculate the Child Support Payable for a particular child.


A breakdown of the Basic Formula is available from the Department of Human Services that can be found here.


child support is the payment that one parent makes to the primary caretaker of the child

What does the Child Support Formula take into account?

The Formula, in calculating the Child Support Payable, will take into account the time that the child spends with each parent. The Department of Human Services also bases the Basic Formula on research into the costs of raising children to determine the exact amount payable for a particular dependent Child.


What if the Formula is unfair to me?



There may be circumstances in which the calculation is unfair to one parent. This can occur if a parent has arranged to minimise their taxable income, a parent has lost their job since an assessment was made, or a child has special needs or attends a more costly private institution.


In circumstances such as this, it is possible to apply to the Child Support Agency to change the assessment. The Department of Human Services will consider the unique circumstances before amending any calculations.