Family Law Child Support – The formula

By Carlos Turini – Family Law SpecialistCarlos Turini

The Costs of Children Table is available from the Dept. of Human Services.

The basic formula applies to parents with one child support assessment and no other dependent children. The formula below is used for most child support assessments.

The steps of the basic formula are:

  • to calculate each parents child support income, which is a parent’s adjusted taxable income minus a self-support amount.
  • the parents child support incomes are combined together.
  • the combined child support income is divided by each individual parents child support income to get the parents income percentage
  • each parents cost and care percentage are calculated using the Human Services Care and Cost Table
  • the cost percentage is subtracted from the income percentage for each parent. The result is called the child support percentage.
  • If it is a negative percentage, that parent is assessed to receive child support because their share of the costs of raising the children is more than met by the amount of care they are providing.
  • If it is a positive percentage, that parent is assessed to pay child support because they are not meeting their entire share of the costs of the child directly through care.  (Different care arrangements for different children may result in different percentages)
  • The costs for each child are based  on the parents’ combined child support income using the costs for children table available on the Dept for Human Services website.
  • The final child support payable is calculated by multiplying the postive child support percentage by the costs of the child, this figure is the child support amount the paying parent needs to transfer to the other parent.

Non-parent carers

If you provide care for a child and you are not the parent, you may be able to receive Child Support from both of the child’s parents if you apply for a Child Support assessment.

Same-sex parents

If you are a separated parent with children from a previous same-sex relationship and already have a Child Support case where you are listed as a non-parent carer, you can ask that your case be changed to reflect your status as a parent.

Estimating your income for child support payments

In some circumstances, if your income changes significantly, you can choose to have your child support assessment based on an estimate of your income for example:

  • if you have experienced the loss of a job or contract
  • have had a significant reduction in hours of work or overtime
  • or have recently started receiving Centrelink benefits.

You may not be able to lodge an estimate if your child support assessment is based on one of the following:

  • a child support agreement
  • a determination made under the change of assessment process, or
  • a court order

If you wish to lodge an estimate of your income, you must follow the current process  as outlined on the Child Support Agency website

Each family is unique and child support can vary according to your situation.

For more information or to make an appointment to see one of our family law solicitors in either our Canberra or Queanbeyan office, contact Carlos Turini – Accredited Family Law Specialist

p: (02) 6206 1300 | e:

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