Private Australian estimate
Child Support
Calculator Australia
Enter the children, care arrangements and parent incomes to estimate child support under the current 2026 rates.
Start my Estimate- Formula 1–6The official formula step by step
- No sign-upPrivate estimate, no account needed
- Calculate in your browserYour estimate stays here unless you save, email or share it
After your estimate
Your estimate is a starting point.
It answers one careful question: what the Australian child support formula produces from the information you entered.
Before you rely on it, check the information most likely to change the outcome—and know when only Services Australia can settle it.
It is based on your entries, the published Australian formula and the applicable annual values. It is not legal advice.
Services Australia alone issues formal child support assessments and may use information or decisions this calculator cannot capture.
A two-minute check
Confirm the three things most likely to move the figure.
You do not need to understand every step in the formula. Start with the information that shapes the result.
The income reflects the situation you meant to test
Child support uses adjusted taxable income. Check that each income figure and any relevant dependent children or other child support cases match the scenario you intended to estimate.
The care pattern is the one you expect to continue
Confirm the nights or percentage of care entered for every child. If care is changing or disputed, the formal assessment may use different information.
Nothing important sits outside the calculation
Agreements, accepted decisions, non-parent carer details and other circumstances can affect an official outcome. The estimate can only use what the calculator asked for and what you entered.
Why might the official assessment be different?
A difference does not automatically mean either result is wrong. It usually means the information or decision behind the calculation is different.
- Services Australia may hold different income or care information.
- A relevant dependant, another child support case or a non-parent carer may change how the formula applies.
- An agreement, review or accepted decision may affect the formal assessment outside this estimate.
Inspect the work
You should be able to see how the estimate was made.
Credibility comes from a traceable method, not a promise of accuracy.
Income, care, children and relevant case details.
The Australian formula and applicable annual values.
A result for the scenario you entered—not an assessment.
Methodology last reviewed .
Methodology and authoritative sources
How the calculation is maintained
The calculator applies the published child support formula, including the formula pathway relevant to the information entered, using the annual values applicable to the assessment year.
What do you need from the estimate now?
I wanted a reliable sense-check
Keep the result together with the details you entered. Recalculate if income, care or the children’s circumstances change.
I need an official amount
Services Australia alone can issue or change a formal child support assessment. Use its separated parents service for the official process.
Go to Services AustraliaThe result does not fit what is happening
Start with why an Estimate and Formal Assessment may differ. If you need help choosing a next route, use child support help.