Child support calculator for Australia

An instant estimate using the same 8-step formula Services Australia applies, with the current 2026 figures. Enter both incomes, the children, and the care split.

Your details

Parent A income Adjusted taxable income, per year

Parent B income Adjusted taxable income, per year

Children aged 0–12

Children aged 13+

Nights per year with Parent A Drag to match your care arrangement

Parent A: 52 nights · 14% Parent B: 313 nights · 86%

Other dependent children (optional)

Children either parent supports in a new family. These reduce that parent's income before the formula runs.

Parent A — aged 0–12

Parent A — aged 13+

Parent B — aged 0–12

Parent B — aged 13+

How this estimate is worked out ▾

1	Child support incomeEach income minus the $31,046 self-support amount
2	Combined child support income
3	Income percentagesEach parent's share of the combined income
4	Care percentagesBased on nights per year
5	Cost percentagesCare converted to a share of costs met directly
6	Child support percentageIncome share minus cost share
7	Costs of the childrenFrom the 2026 Costs of the Children table
8	Annual rate payablePositive child support percentage × costs of the children

How child support is calculated in 2026

Child support in Australia is assessed by Services Australia under the Child Support (Assessment) Act 1989 using an income shares formula. The idea is simple even though the maths isn't: work out what the children cost, then split that cost between the parents according to their share of combined income, giving credit for the care each parent provides directly.

The self-support amount

Before anything else, $31,046 is deducted from each parent's adjusted taxable income for 2026. This is the amount the formula sets aside for a parent's own living costs, and it's indexed every January against average weekly earnings.

The costs of the children

The combined remaining income is applied to the government's Costs of the Children table. Costs rise with income but at decreasing rates, are higher for teenagers than for under-13s, and stop increasing once combined child support income passes $232,843.

Care and cost percentages

Care below 52 nights a year (14%) doesn't reduce child support. From 52 nights, care converts to a cost percentage — 24% for regular care, rising through shared care levels to 50% at equal time. A parent pays when their income share is bigger than their cost share.

Minimum and fixed rates

Low-income payers may instead pay the minimum annual rate of $551 per case, or the fixed rate of $1,825 per child where income was low but the parent didn't receive income support. These are also 2026 figures and change each year.

Guides

How the care percentage worksNights per year, the 52-night threshold, and how care converts to a cost percentage. What counts as adjusted taxable incomeSalary, fringe benefits, super contributions, investment losses and more. Child support with 50/50 careWhy equal care doesn't always mean zero child support, with a worked example.

This is an estimate, not advice or an assessment. It applies the published 2026 formula to the numbers you enter. Services Australia is the only body that can make a formal child support assessment, and factors such as multiple cases, non-parent carers, income determinations, agreements and change-of-assessment decisions can produce a different result. For your official figure, contact Services Australia. Nothing here is legal or financial advice.