Below regular care0–13%
0–51 nights/year
- Formula cost
- 0% cost
- Typical role
- Payer only
Updated for 2026 rates
Child Support Calculator Australia
Estimate what you may pay or receive using the Australian child support formulas and 2026 indexed rates.
Handles shared care, relevant dependent children, multiple child-support cases, and non-parent carers.
Under 1 minuteNo sign-upYour figures stay on this device unless you request help
Method and responsibility
About this calculator
Built by Sam, a former child support officer with Services Australia. The calculation applies the legislated methods and is maintained against current Services Australia rates, DSS guidance, and the worked examples documented in our methodology.
Estimate only. Services Australia issues formal assessments.
Read the methodology and update processCare percentage thresholds
How many nights of care you provide directly affects how much child support is paid. Services Australia uses these statutory thresholds:
| Care level | Care % | Nights/year | Cost % | Payer role |
|---|---|---|---|---|
| Below regular care | 0–13% | 0–51 | 0% | Payer only |
| Regular care | 14–34% | 52–127 | 24% | Payer onlynil liability possible |
| Shared care | 35–47% | 128–175 | 25% +2% per pt >35% | Income determines the payer |
| 48–52% | 176–189 | 50% | ||
| 53–65% | 190–237 | 51% +2% per pt >53% | ||
| Primary care | 66–86% | 238–313 | 76% | nil liability possiblePayee only |
| Above primary care | 87–100% | 314–365 | 100% | Payee only |
Regular care14–34%
52–127 nights/year
- Formula cost
- 24% cost
- Typical role
- Payer only; nil liability may be possible
Shared care35–47%
128–175 nights/year
- Formula cost
- 25% + 2% per point over 35%
- Typical role
- Income determines the payer
Shared care48–52%
176–189 nights/year
- Formula cost
- 50% cost
- Typical role
- Income determines the payer
Shared care53–65%
190–237 nights/year
- Formula cost
- 51% + 2% per point over 53%
- Typical role
- Income determines the payer
Primary care66–86%
238–313 nights/year
- Formula cost
- 76% cost
- Typical role
- Payee only; nil liability may be possible
Above primary care87–100%
314–365 nights/year
- Formula cost
- 100% cost
- Typical role
- Payee only
Not sure which band you fall into? Enter your nights of care and the calculator maps it to the correct cost percentage automatically.
Calculate my care percentageExplore the details
Common scenarios
50/50 shared care — does child support still apply?See why equal care can still produce a payment when parental incomes differ.Estimating child support for one childUnderstand how income, age, and care combine for one child.One parent on a very low income or no incomeLearn when minimum and fixed annual rates can affect the estimate.Income changed since your last assessmentCompare updated inputs, then understand the Change of Assessment pathway.What income goes into the formula?Find the adjusted taxable income figure the formula uses.Worked examples for all six formulasReview reproducible inputs, pathways, and annual results for Formula 1 to 6.
Calculator help and references
Frequently asked questions
How much child support will I pay?
Child support in Australia is calculated using an 8-step formula under the Child Support (Assessment) Act 1989. The amount depends on both parents' adjusted taxable incomes, the percentage of time each parent cares for the children, and how many children are involved. There's no single figure that applies to everyone — the calculation varies significantly based on those inputs.
The fastest way to get your estimate is to use the calculator above. It takes the same inputs Services Australia uses and gives you a result in under 1 minute. → Calculate your estimate
How is child support calculated in Australia?
Child support uses an 8-step formula. In plain terms, it works like this:
- Both parents' adjusted taxable incomes are assessed
- A self-support deduction ($31,046 in 2026) is subtracted from each parent's income
- The care percentage for each parent is determined
- The costs of raising children (from a standard table) are divided between parents based on income and care
The result is the annual child support amount. Our calculator applies this logic automatically — you enter your figures, it does the maths. For a detailed breakdown of each formula type, see our child support formula guide.
What income is used to calculate child support?
Child support uses your adjusted taxable income (ATI), not your take-home pay or gross salary alone. ATI includes:
- Taxable income (salary, wages, business income)
- Reportable fringe benefits
- Reportable employer super contributions
- Total net investment losses
It does not include Family Tax Benefit or most Centrelink payments. In 2026, a self-support deduction of $31,046 is removed from each parent's ATI before the formula is applied — only income above this threshold counts. Use your most recent Notice of Assessment from the ATO as your starting figure.
What care percentage do I need for child support to change?
Care percentage has four key thresholds in the formula:
| Care % | Nights/year | Nights/fortnight | Care level | Cost % |
|---|---|---|---|---|
| 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% + 2% per point over 35% |
| 48–52% | 176–189 | 7 | Shared care | 50% |
| 53–65% | 190–237 | 8–9 | Shared care | 51% + 2% per point over 53% |
| 66–86% | 238–313 | 10–12 | Primary care | 76% |
| 87–100% | 314–365 | 13–14 | More than primary care | 100% |
Enter your exact care arrangement into the calculator to see how your cost percentage affects the payment.
How does 50/50 shared care affect child support?
Equal care does not automatically mean zero child support.
At 50/50 care, both parents are treated as sharing the costs of the children equally — but child support is still calculated based on the income difference between the two parents. The parent with the higher income typically pays the parent with the lower income, even when care is split equally.
The exact amount depends on how large the income gap is. → Calculate your 50/50 shared care estimate
What is the minimum child support payment in Australia?
There is a minimum annual child support amount that applies even if the paying parent has little or no income. In 2026, that figure is $551 — indexed each year in line with the Consumer Price Index. If the paying parent earns nothing at all, the minimum rate still applies. It is not reduced to zero. The minimum assessment reflects the expectation that all parents contribute something toward the cost of raising their children. You can use the calculator to see how payments scale from the minimum as income increases.
How much child support for one child?
The amount for a single child varies widely based on both parents' incomes and the care arrangement. As a reference: a paying parent earning $80,000 with the other parent earning $50,000 and 50/50 care would typically pay in the range of $5,000–$7,000 annually — but this is illustrative only.
The only way to get a figure that reflects your actual income and care percentage is to run the calculator. → Calculate child support for one child
Can child support be reduced if my income drops?
Yes, in some circumstances. Child support assessments are not permanent. If your income has dropped significantly since your last assessment, you may be able to apply for a Change of Assessment — a formal process through Services Australia to have your payments recalculated.
Changes are assessed against eight specific grounds set out in the legislation, including major income changes, shifts in care arrangements, school fees or medical expenses, and supporting a new family. If both parents agree on a different amount, they can also enter a binding child support agreement.
Browse our child support guides and resources for in-depth explanations of the formula, care arrangements, and agreements.
