2.4.6 The costs of the child

Context

The costs of a child are determined by the parents' incomes, the number of children and the age of the children. The costs are calculated using the Costs of the Children Table. The child support formulas then determine how these costs will be met.

Act references

CSA Act section 5, section 46, section 47, section 55E to section 55HA, Schedule 1

On this page

The Costs of the Children Table

The Costs of the Children Table is updated annually. A new table is published for each calendar year, to be used in making assessments for child support periods that start in that year. The costs are adjusted according to the relevant Male Total Average Weekly Earnings (MTAWE) figure (section 155). The Costs of the Children Table for each year from the 2007 calendar year is included at 2.4.2.

The Costs of the Children Table identifies the costs of the children based on the parents' combined child support income (for most formulas), the parent's child support income (when the income of only 1 parent is used) or a parent's initial child support income (for relevant dependent child amount and multi-case allowance calculations).

The Costs of the Children Table is used to calculate the:

The table is located at CSA Act Schedule 1 clause 1 and shows the percentages used to work out the costs of the children for all income levels and for different numbers and ages of children. Information regarding the use of the table is included at clauses 2, 3 and 4 of Schedule 1.

Parents' combined child support income or parent's child support income
Fraction of MTAWE 0 to 0.5 0.5 to 1 1 to 1.5 1.5 to 2 2 to 2.5 Over 2.5
Child support children Costs of the children
All children aged 0-12 years
1 child 17% 15% 12% 10% 7%  
2 children 24% 23% 20% 18% 10%  
3 children 27% 26% 25% 24% 18%  
All children aged 13+ years
1 child 23% 22% 12% 10% 9%  
2 children 29% 28% 25% 20% 13%  
3 children 32% 31% 30% 29% 20%  
At least 1 child aged 0-12 years and 1 child aged 13+ years
2 children 26.5% 25.5% 22.5% 19% 11.5%  
3 children 29.5% 28.5% 27.5% 26.5% 19%  

The Costs of the Children Table is divided into columns, with each column representing an income bracket that is a fraction of MTAWE. The parents' combined child support income is used in determining the costs of the children in child support formulas 1, 2, 3 and 4 (sections 55G(1) and 55HA(1)). Only one parent's income is used in determining the costs of the children in child support formulas 5 and 6 (sections 55G(2) and 55HA(2)).

If the income used to calculate the costs of the child is greater than 2.5 times MTAWE, then the costs are capped at the amount in the last column of the Costs of the Children Table.

Example: The parents' combined child support income is $210,000, for a child support period starting 6 April 2021. There are 2 children over 12. The costs of the children are capped at $45,401, the number in the last column of the '2 children' row in the table for older children (13+ years).

Ages of the children

The Costs of the Children Table is divided into children aged 0-12 years and 13+ years. There are also mixed age amounts in the table for use when calculating the costs of a child using the basic formula method or the costs of a relevant dependent child. The mixed age amounts are an average of the amounts for children aged 0-12 years and 13+ years.

The costs of the children for a day in the child support period are calculated by identifying the age of the children for that day (section 55G(4)). If a child will turn 13 within the child support period the costs of the child will be calculated differently for the periods before and after the child's 13th birthday.

Example: Sam and Maria have 3 children, Alex aged 12, Nicholas aged 9 and Michael aged 8. The child support period starts on 6 September 2020. Alex's 13th birthday is on 12 November 2020.

The costs of the children are calculated using the table for 3 younger children (0-12 years) for the period 6 September to 11 November 2020. For the period 12 November 2020 to 5 December 2021 the costs are calculated using the mixed age amounts in the Costs of the Children Table.

Number of children

The ranges for the number of children are 1, 2 or 3 or more. Where there are 4 or more children, the same costs as for 3 children are used. When calculating costs for more than 3 children, the ages of the oldest 3 children are used (section 55G(4)).

Example: Ivan and Peta have 4 children, Adam aged 15, Deborah aged 13, Bristol aged 10 and Peta aged 8. The child support period starts on 6 September 2020.

The costs of the children are calculated using the ages of the 3 eldest children. As the 3 eldest children are 2 older and 1 younger child, the mixed age amounts in the Costs of the Children Table for 2020 are used. The costs of each child will be the total costs of the children divided by the actual number of children, which is 4.

Calculating the costs of a child - the basic formula method

The method used to work out the costs of the children is specified at section 55G. The steps, using the Costs of the Children Table, are:

Step 1. Locate the appropriate income bracket (column).

Step 2. Identify the ages of the children - all under 13, all 13 and over or of mixed ages. Go to the corresponding range (box).

Step 3. Determine if there are 1, 2 or 3 or more children and identify the correct row.

Step 4. Follow the instructions in the box to determine the costs of the children.

If there is only 1 child, the costs determined at Step 4 are the costs of the child (section 55H(a)). Otherwise, the costs of each child are worked out by dividing the costs determined at Step 4 by the number of children (section 55H(b)).

The amount calculated is rounded, to the nearest dollar (below 49.5 cents rounded down, 49.5 cents and above rounded up), to a dollar figure at each step.

Example: The parents' combined child support income is $86,000, for a child support period starting 6 September 2020. There are 2 children over 12. The box where the respective column and row intersect shows that the costs are the total of $21,867 plus 25c for each $1 over $76,726.

Costs of the children = $21,867 + (($86,000 − $76,726) × $0.25)
= $21,867 + ($9,274 × $0.25)
= $21,867 + $2,319 (rounded)
= $24,186

Costs of a child = $12,093 ($24,186 divided by 2 children)

Calculating the costs of a child - multiple case method

The method used to work out the costs of the children where one or both of the parents has multiple child support cases is specified in section 55HA. The mixed age range of the Costs of the Children Table is not used for multiple case calculations, as the costs of each child are worked out as though all of the children in the case are the same age.

The steps to be used for each case, using the Costs of the Children Table, are:

Step 1. Locate the appropriate income bracket (column).

Step 2. Identify the number of children in the case for which the costs are being determined.

Step 3. For each child in the case, identify the age of the child.

Step 4. For each child in the case, calculate the cost of the child as though all of the children in the case were the same age as that child.

Example: A child of the case, Diane is 12. There are 2 other children in the case who are 14 and 15. For this step calculate the cost of the child Diane as though all children were 12 (i.e. 3 children under 13).

Step 5. Identify the box in the relevant column in the costs of the children table that covers the number of children of that age.

Step 6. Follow the instructions in the box to work out the costs of the children.

Step 7. To work out the costs of the child, divide the amount worked out at Step 6 by the number of children (costs of 2 children the same age as Diane).

Repeat Steps 3 to 7 to work out the costs of each child in the case. Repeat Steps 1 to 7 for each child support case.

Example: Beatrix has 2 child support cases. In case 1, the parents' combined child support income is $86,000 and there are 2 children, Phoebe aged 4 and Anthony aged 7. In case 2, the parent's combined child support income is $101,000 and there are 2 children, Elvira aged 9 and Bart aged 15.

In case 1, the box where the respective column and row intersect shows that the costs of Phoebe are the total of $18,030 plus 20c for each $1 over $76,726.

Costs of the children = $18,030 + (($86,000 − $76,726) × $0.20)
= $18,030 + ($9,274 × $0.20)
= $18,030 + $1,855 (rounded)
= $19,885

Costs of Phoebe = $9,943 ($19,885 divided by 2 children and rounded)

The same calculation is used to work out the costs of the child Anthony = $9,943.

In case 2, the box where the respective column and row intersect shows that the costs of Elvira are the total of $18,030 plus 20c for each $1 over $76,726 (costs of 2 children the same age as Elvira).

Costs of the children = $18,030 + (($101,000 − $76,726) × $0.20)
= $18,030 + ($24,274 × $0.20)
= $18,030 + $4,855 (rounded)
= $22,885

Costs of Elvira = $11,443 ($22,885 divided by 2 children and rounded)

For the elder child Bart, the box where the respective column and row intersect shows that the costs of Bart are the total of $21,867 plus 25c for each $1 over $76,726 (costs of 2 children the same age as Bart).

Costs of the children = $21,867 + (($101,000 − $76,726) × $0.25)
= $21,867 + ($24,274 × $0.25)
= $21,867 + $6,069 (rounded)
= $27,936

Costs of Bart = $13,968 ($27,936 divided by 2 children)

Calculating a relevant dependent child amount

If a parent has a relevant dependent child in their care the cost of the parent caring for that child is taken into account in calculating their child support assessment. The costs are included by deducting a 'relevant dependent child amount' from the parent's 'initial child support income' (their adjusted taxable income less the self-support amount) at Step 1 of the basic formula. Only the initial child support income of the parent who has the relevant dependent child is used to calculate the costs of the relevant dependent child.

A parent's relevant dependent child amount is the total of the amounts worked out for each relevant dependent child of the parent using the following steps (section 46).

Step 1. Deduct the parent's self-support amount from their adjusted taxable income to determine their initial child support income.

Step 2. Work out the parent's percentage of care for the child. (Note: A parent who lives fulltime with a relevant dependent child has 100% care of that child, even if they also live with a new partner. The new partner's income is omitted from the calculation of the relevant dependent child amount, and therefore so is any contribution they make to the costs of the relevant dependent child).

Step 3. Work out the parent's cost percentage for the child (section 55C).

Step 4. Work out the costs of the child using the 'basic formula method' described above, using the parent's initial child support income only (section 55G). (Note: If there is only one relevant dependent child, the costs determined at Step 4 of the 'basic formula method' are the costs of the relevant dependent child (section 55H(a)). Otherwise, the costs of each relevant dependent child are worked out by dividing the costs determined at Step 4 by the number of relevant dependent children (section 55H(b))).

Step 5. Work out the parent's relevant dependent child amount using the following calculation. If there is more than one relevant dependent child, sum the resulting amounts for each child.

Parent's cost percentage for the child under Step 3 × costs of the child under Step 4

Example: Sung-soo has an adjusted taxable income of $66,000 and is the parent of 2 relevant dependent children: Abigail aged 3 and Suellen aged 6. Sung-soo has 100% care of Abigail and Suellen. The self support amount for 2020 is $25,575.

The initial child support income is $66,000 − $25,575 = $40,425 (Step 1).

Sung-soo has 100% care of Abigail and Suellen (Step 2). The cost percentages are 100% for Abigail and Suellen (Step 3).

The box where the respective column and row intersect using Sung-soo's initial child support income shows that the costs of Abigail and Suellen are the total of $9,207 plus 23c for each $1 over $38,363.

Costs of the children = $9,207 + (($40,425 − $38,363) × 0.23)
= $9,207 + ($2,062 × $0.23)
= $9,207 + $474 (rounded)
= $9,681

Costs of Abigail = $4,841 ($9,681 divided by 2 children and rounded) (Step 4)

Costs of Suellen = $4,841 ($9,681 divided by 2 children and rounded) (Step 4)

As Sung-soo has a cost percentage of 100% for Abigail, the relevant dependent child amount is $4,841 (100% × $4,841).

As Sung-soo has a cost percentage of 100% for Suellen, the relevant dependent child amount is $4,841 (100% × $4,841).

Sung-soo's relevant dependent child amount is $9,681 (the sum of each of the child amounts at Step 4) (Step 5).

The relevant dependent child amount is deducted from the parent's initial child support income to determine their child support income.

Example: Sylvester has an adjusted taxable income of $70,000 and is the parent of a relevant dependent child Anna aged 3. Sylvester has 100% care of Anna. The self-support amount for 2020 is $25,575.

The initial child support income is: $44,425.

The relevant dependent child amount is: $7,461.

The parent's child support income is: $36,964.

See 2.9.5 for information about amending an assessment to recognise a relevant dependent child.

Last reviewed: 10 May 2021