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Read about parents with 2 or more assessments.
This page is for general information. To calculate an estimate of your child support payments you can use our child support estimator.
Basic 8 step formula
| Step | What we do | This step is about |
|---|---|---|
| 1. Work out each parent’s child support income | We calculate each parent’s child support income. This is a parent’s adjusted taxable income minus a self-support amount and any relevant dependant allowance. For more information about relevant dependant allowances, go to child support assessments and second families. A parent may be able to estimate their income. Read more about income used in calculating a child support assessment. | Income |
| 2. Work out the parents’ combined income | We add both parents’ incomes to work out a combined child support income. | Income |
| 3. Work out each parent’s income percentage | We work out each parent’s income percentage by dividing each income by the combined total. | Income |
| 4. Work out each parent’s percentage of care | We calculate each parent’s percentage of care. | Care |
| 5. Work out each parent’s cost percentage | We work out each parent’s cost percentage using the Care and Cost table. | Care |
| 6. Work out each parent’s child support percentage | We subtract the cost percentage from the income percentage for each parent. We call this the child support percentage. The result will determine if a parent pays or gets child support. If it’s a negative percentage, we assess that parent as the parent to get child support. This is because their share of costs for the child is more than the amount of care they provide. If it’s a positive percentage, we assess that parent as the parent to pay child support. This is because they’re not meeting their share of the costs for the child directly through care. If you have different care arrangements for various children, you might have different child support percentages for each child. We go on to steps 7 and 8 using only the positive child support percentage. | Child support percentage |
| 7. Work out the costs of children | We work out the costs for each child based on the parents’ combined total income. We do this by using the Costs of Children table. | Costs of children |
| 8. Work out the child support amount | We work out the total amount of child support payable. We do this by multiplying the positive child support percentage by the costs of the child. If we assess both parents are to pay each other, we offset these amounts before arriving at the final figure. This final figure is the amount the paying parent needs to pay the other parent. | Child support to pay |
Care and cost table
Your care percentage is the amount of time you spend with the child. This helps us to work out your cost percentage.
Your cost percentage is your share of the child’s costs that you meet directly through care.
| Care percentage | Equal to number of nights a year | Equal to number of nights a fortnight | Care level | Cost percentage |
|---|---|---|---|---|
| 0-13% | 0-51 | 1 | Less than regular care | 0% |
| 14-34% | 52-127 | 2-4 | Regular care | 24% |
| 35-47% | 128-175 | 5-6 | Shared care | 25% plus 2% for every percentage point over 35% of care |
| 48-52% | 176-189 | 7 | Shared care | 50% |
| 53-65% | 190-237 | 8-9 | Shared care | 51% plus 2% for every percentage point over 53% of care |
| 66-86% | 238-313 | 10-12 | Primary care | 76% |
| 87-100% | 314-365 | 13-14 | More than primary care | 100% |
Read about how your percentage of care affects your child support.
Costs of children
The Costs of Children tables recognise that raising children costs different amounts for different people. Because of this we work out your children’s costs based on all of the following. The:
- parents combined child support income
- number of children
- children’s ages.
About the tables
Steps 1 and 2 of the basic 8 step formula explain what combined child support income is.
Under the formula, we deduct an amount for each parent to support themselves. We calculate the costs of raising children according to the remaining combined child support income of both parents. We divide the costs between the parents according to their share of the combined income.
The Costs of Children table represents net costs after Family Tax Benefit. All the figures in these tables are for child support periods starting in 2025.
Read about Costs of Children for past years in the Child Support Guide on the Department of Social Services website.
Children aged 12 and under
| Parents combined child support income | Cost of 1 child | Cost of 2 children | Cost of 3 or more children |
|---|---|---|---|
| $0 to $44,762 | 17c for each $1 | 24c for each $1 | 27c for each $1 |
| $44,763 to $89,523 | $7,610 plus 15c for each $1 over $44,762 | $10,743 plus 23c for each $1 over $44,762 | $12,086 plus 26c for each $1 over $44,762 |
| $89,524 to $134,285 | $14,324 plus 12c for each $1 over $89,523 | $21,038 plus 20c for each $1 over $89,523 | $23,724 plus 25c for each $1 over $89,523 |
| $134,286 to $179,046 | $19,695 plus 10c for each $1 over $134,285 | $29,990 plus 18c for each $1 over $134,285 | $34,915 plus 24c for each $1 over $134,285 |
| $179,047 to $223,808 | $24,171 plus 7c for each $1 over $179,046 | $38,047 plus 10c for each $1 over $179,046 | $45,658 plus 18c for each $1 over $179,046 |
Income over $223,808 Costs don’t go up past this cap | $27,304 | $42,523 | $53,715 |
Read more about parents combined child support income.
Children aged 13 or older
| Combined child support income for one year | Cost of 1 child | Cost of 2 children | Cost of 3 or more children |
|---|---|---|---|
| $0 to $44,762 | 23c for each $1 | 29c for each $1 | 32c for each $1 |
| $44,763 to $89,523 | $10,295 plus 22c for each $1 over $44,762 | $12,981 plus 28c for each $1 over $44,762 | $14,324 plus 31c for each $1 over $44,762 |
| $89,524 to $134,285 | $20,142 plus 12c for each $1 over $89,523 | $25,514 plus 25c for each $1 over $89,523 | $28,200 plus 30c for each $1 over $89,523 |
| $134,286 to $179,046 | $25,513 plus 10c for each $1 over $134,285 | $36,705 plus 20c for each $1 over $134,285 | $41,629 plus 29c for each $1 over $134,285 |
| $179,047 to $223,808 | $29,989 plus 9c for each $1 over $179,046 | $45,657 plus 13c for each $1 over $179,046 | $54,610 plus 20c for each $1 over $179,046 |
Income over $223,808 Costs don’t go up past this cap | $34,018 | $51,476 | $63,562 |
Read more about parents combined child support income.
Children of mixed ages
| Combined Child Support income for one year | Cost of 2 children | Cost of 3 or more children |
|---|---|---|
| $0 to $44,762 | 26.5c for each $1 | 29.5c for each $1 |
| $44,763 to $89,523 | $11,862 plus 25.5c for each $1 over $44,762 | $13,205 plus 28.5c for each $1 over $44,762 |
| $89,524 to $134,285 | $23,276 plus 22.5c for each $1 over $89,523 | $25,962 plus 27.5c for each $1 over $89,523 |
| $134,286 to $179,046 | $33,347 plus 19c for each $1 over $134,285 | $38,272 plus 26.5c for each $1 over $134,285 |
| $179,047 to $223,808 | $41,852 plus 11.5c for each $1 over $179,046 | $50,134 plus 19c for each $1 over $179,046 |
Income over $223,808 Costs don’t go up past this cap | $47,000 | $58,639 |
Read more about parents combined child support income.