Child Support: How Much Will I Pay in 2026?

Child support in Australia isn't just a flat number someone picks — it's worked out using an 8-step formula administered by Services Australia. The formula considers both parents' incomes, the number of children, the ages of the children, and how much time each parent spends caring for them.

Here's the simplified version. Both parents' adjusted taxable incomes (ATI) are added together. A "self-support amount" is deducted for each parent — in 2026, that's $29,323 per year (one-third of the average weekly earnings figure). Then each parent's share of the combined income determines their percentage of the costs of the children.

The "costs of the children" figure comes from a lookup table based on combined income and the ages of the children. For example, two children aged under 13 with a combined parental income of $120,000 might have an assessed cost of around $27,600 per year. The parent who has less care time pays their share of that cost to the other parent.

There's an income cap of $193,469 for 2026 — any income above this amount is ignored for child support purposes. Use our child support calculator to run the numbers for your specific situation.

Care percentage is one of the biggest levers in the child support formula. The more nights the children spend with you, the less child support you pay (or the more you receive). Here's how it breaks down:

• 0–51 nights/year (0–13%) — "Below regular" care. You get no cost percentage credit and pay the maximum amount.
• 52–127 nights/year (14–34%) — "Regular" care. You get a 24% cost percentage, reducing what you pay.
• 128–175 nights/year (35–47%) — "Shared" care. You get a cost percentage based on actual nights — the reduction is significant.
• 176–255 nights/year (48–69%) — "Primary" care. You're likely receiving child support rather than paying it.
• 256+ nights/year (70%+) — "Above primary" care. You receive the full assessed amount.

The jump from 127 to 128 nights is massive in financial terms. Going from "regular" to "shared" care can reduce a child support assessment by 30–50%. This is why care arrangements are often the most contested part of separation negotiations.

Services Australia determines care percentage based on a care arrangement — usually a parenting plan, court order, or written agreement. If there's a dispute about the actual care being provided, either parent can ask for a care review.

Your child support obligation is directly tied to your income — specifically your Adjusted Taxable Income (ATI). The higher your income compared to the other parent's, the more you'll pay.

Let's run through a quick example. Say you earn $100,000 and your ex-partner earns $50,000. You have two children under 13, and they spend 4 nights per fortnight with you (about 28% care). After deducting the self-support amount from each parent, your combined child support income is around $121,354. Your share of that combined income is about 66%.

The assessed cost of two children under 13 at that income level is roughly $27,500/year. Your 66% share is $18,150. But your care percentage gives you a 24% cost offset of $6,600, so you'd pay approximately $11,550/year — or about $962/month.

If your income changes by more than 15%, you can ask Services Australia to reassess. A new job, redundancy, or going part-time are all valid reasons for a reassessment. You can also apply for a change of assessment in special circumstances — like high medical costs, school fees, or travel costs for contact visits.

Here are some real-world scenarios to give you a feel for typical assessments in 2026:

Scenario 1: Average earner, minimal care. You earn $85,000, ex earns $40,000. One child aged 8. You have the child every second weekend (52 nights). Assessment: roughly $9,200/year ($767/month).

Scenario 2: Higher earner, shared care. You earn $130,000, ex earns $60,000. Two children aged 5 and 10. You have 40% care (146 nights). Assessment: roughly $8,400/year ($700/month). Shared care makes a big difference here.

Scenario 3: Both earn similar amounts. You earn $75,000, ex earns $70,000. One teenager aged 15. You have 35% care (128 nights). Assessment: roughly $1,800/year ($150/month). When incomes are close and care is nearly shared, the amounts are small.

Scenario 4: One parent not working. You earn $95,000, ex earns $0. Two children under 13. You have standard every-second-weekend care. Assessment: roughly $16,500/year ($1,375/month). When one parent has no income, the full cost falls on the other.

These are estimates — your actual assessment depends on the precise formula. Run yours through our child support calculator for an accurate figure.

The income figure used for child support is your Adjusted Taxable Income (ATI), which is broader than just your salary. ATI includes:

• Taxable income — your gross salary minus deductions as shown on your tax return
• Reportable fringe benefits — salary-packaged items like cars, laptops, or meal entertainment
• Target foreign income — overseas income that might not appear on your Australian tax return
• Total net investment losses — if you're negatively gearing a property, that loss gets added back
• Reportable super contributions — salary sacrifice into super above the compulsory amount

This is important: you can't reduce your child support by salary sacrificing heavily into super. The extra contributions get added back into your ATI. Similarly, negatively geared properties don't reduce your assessed income — the net rental loss is reversed.

Services Australia generally uses your most recent tax return to determine your ATI. If your income has changed significantly since then, you can lodge an estimate — but be careful, because if your actual income turns out higher, you may face a retrospective increase and owe back-payments.

If you think the other parent is hiding income or understating their earnings, you can ask Services Australia to investigate. They have the power to access ATO records and can issue amended assessments if they find discrepancies.