Child Support Calculator Australia in Under 2 Mins

Child Support Calculator Australia

The Child Support Estimator helps you determine your estimated child support payments or receipts based on the official Australian Government formula. Simply input details regarding both parents’ taxable incomes, the number of children, and your care arrangements to get a clear overview of your potential annual and monthly assessment.

For a full estimate of how much child support may be payable or received, you can also use our:

Child Support Calculator

Based on the official Australian Government formula

Assessment Year

Using 2026 government rates.

Your Taxable Income Annual adjusted taxable income before tax.

Other Parent's Income Annual adjusted taxable income before tax.

Children (0–12 years)

Children (13–17 years)

Your Care (nights per fortnight) Average overnight stays you provide per fortnight.

Equivalent nights per year Override with exact annual nights if known.

Estimate Results

Annual assessment estimate

Status

–

Annual Amount $0

Monthly Amount $0

Weekly Amount $0

Important Disclaimer: This calculator provides an estimate only based on publicly available information regarding the Australian child support formula and current parameters as at 2025. It is not legal advice and should not be relied upon as a final assessment.

Child support calculations can vary depending on numerous factors including care arrangements, additional dependants, multi-case assessments, income changes, or other circumstances that may affect the statutory formula.

While reasonable efforts are made to maintain accuracy, this tool is an independent estimator and results may differ from calculations performed by Services Australia, which provides the official child support assessment.

You should always verify your situation directly with Services Australia or seek independent legal advice before making financial decisions based on these estimates.

How it Works Component

How This Calculator Works

We apply the official 8-Step Formula set out in the Child Support (Assessment) Act 1989, using the legislated Costs of Children tables published by Services Australia. Values are indexed annually.

Phase 1: The Income Pool

1 Child Support Income
We subtract the Self-Support Amount ($31,046 in 2026, $29,841 in 2025) from each parent's taxable income. The remainder is the income available for child support.
2 Combined Child Support Income
Both parents' child support incomes are added together to form the combined pool used to calculate the costs of the children.
3 Income Percentage
Each parent's child support income is divided by the combined total to determine their share of responsibility.

Phase 2: The Care Credit

4 Care Percentage
Your nights per fortnight are converted to annual nights, then divided by 365 to produce a care percentage. For example, 5 nights per fortnight equals 130 nights per year (35.6%). Use our care percentage calculator to get an estimate.
5 Cost Percentage
Your care percentage is converted to a cost credit using the legislated table in section 55C. The table uses stepped whole percentage points. For example, 14% to 34% care equals a fixed 24% cost credit. Between 35% and 47%, the credit increases by 2% for each whole percentage point above 35%.
6 Child Support Percentage
Your cost credit (Step 5) is subtracted from your income share (Step 3). A positive result means you pay. A negative result means you receive.

Phase 3: The Assessment

7 Costs of the Children

The combined child support income is applied to the legislated Costs of Children table, which uses five income bands (0.5 to 2.5 times MTAWE) with a base amount plus marginal rate at each band. Costs depend on the number of children and whether they are aged 0 to 12, 13 and over, or mixed ages. Income above 2.5 times MTAWE is capped.

8 Annual Amount

The total cost of the children (Step 7) is multiplied by your child support percentage (Step 6). If positive, you pay that amount annually. If negative, you receive it. Amounts are rounded to the nearest whole dollar at each step, as required by the legislation.

Low Income Rules (2026 values)

Minimum Annual Rate ($551/yr)

Applies where the formula produces a lower amount and the paying parent has below-regular care (less than 14%). Parents with regular care or more are not subject to the minimum rate.

Fixed Annual Rate ($1,825/yr per child)

Applied by Services Australia where a paying parent has low taxable income and is not receiving income support. Capped at three children per assessment.