Why care percentage matters so much
In the Australian child support system, the number of nights your children spend with each parent is one of the most powerful variables in the formula. A shift of even one night per week can move you from one care band to another, potentially changing your child support by thousands of dollars per year.
Understanding how care percentage works helps you make informed decisions about parenting arrangements — not just for financial reasons, but to ensure the arrangement genuinely reflects the time each parent spends with the children.
Use our Care Percentage Calculator to convert your nights into a percentage and see which care band you fall into.
Important: This article is general information only and not legal advice. For advice specific to your situation, contact Services Australia on 131 272 or speak with a family lawyer.
How nights convert to a percentage
Services Australia calculates care percentage based on the number of nights a child spends with each parent over a 12-month period (365 nights total). The formula is straightforward:
Care percentage = (nights with parent / 365) x 100
So if your child spends 4 nights per week with you on average:
- 4 nights x 52 weeks = 208 nights per year
- 208 / 365 = 57% care
And the other parent has:
- 3 nights x 52 weeks = 157 nights per year
- 157 / 365 = 43% care
The 5 care bands
Your exact percentage is then placed into one of five care bands. These bands determine the cost percentage used in the child support formula — essentially, how much of the children's costs each parent is considered to be already covering through direct care.
| Care level | Nights per year | Care % | Cost % credited |
|---|---|---|---|
| Below regular | 0-51 | 0-13% | Nil (0%) |
| Regular | 52-127 | 14-34% | 24% |
| Shared (lower) | 128-175 | 35-47% | 25% + 2% for each 1% above 35% |
| Shared (equal) | 176-189 | 48-52% | 50% (effectively) |
| Primary / above | 190-365 | 53-100% | 51%+ (mirroring the shared bands) |
The critical thresholds
Some thresholds matter more than others:
- 52 nights (14%): The jump from below-regular to regular care. Below 52 nights, the parent receives zero cost credit. At 52 nights, they suddenly receive a 24% cost credit. This is the single biggest jump in the entire system.
- 128 nights (35%): The transition into shared care. The cost percentage starts scaling more gradually from here.
- 176 nights (48%): True shared care begins — both parents are treated as roughly equal carers.
How holidays and school breaks are counted
Care percentage is based on actual care over the year, not just the regular weekly pattern. This means:
- School holidays are counted as they actually occur. If you have the children for 3 extra weeks during school holidays, those 21 nights are added to your total.
- Public holidays and long weekends count as regular nights with whichever parent has care.
- Special occasions like birthdays, Christmas, and Easter are counted based on where the child actually sleeps that night.
This is why your co-parenting schedule should account for holidays explicitly. A parent who has every-other-weekend during term time but gets half the school holidays could have a very different care percentage than the regular pattern suggests.
What happens when care changes
If your actual care pattern changes — say, from 3 nights to 4 nights per week — either parent can notify Services Australia. Common triggers include:
- A child starting school (which may make a midweek overnight impractical)
- A parent relocating for work
- A child expressing a preference as they get older
- New parenting orders from the Federal Circuit and Family Court
Services Australia can update the care percentage from the date the change actually occurred. If you and the other parent disagree about the level of care, Services Australia will investigate and make a determination based on the evidence available.
What evidence counts?
If there's a dispute about care levels, Services Australia may consider:
- Parenting orders or written agreements
- School records showing who drops off and picks up
- Calendars or diaries tracking overnight stays
- Statutory declarations from each parent
Keeping a simple record — even a shared calendar or diary — can save enormous headaches if there's ever a dispute. The Care Percentage Calculator includes space to map out your actual pattern.
Disputed care: the interim period
When parents disagree about care levels, Services Australia makes a determination about what it believes the actual care arrangement is. During the interim period (while the dispute is being resolved), child support may be calculated on an interim care determination. Once the actual care is established, arrears or credits may apply.
Common arrangements and their care percentages
Here's how popular parenting arrangements translate into care percentages:
| Arrangement | Nights/year (approx) | Care % | Care band |
|---|---|---|---|
| Every other weekend (Fri-Sun) | 52 | 14% | Regular |
| Every other weekend + midweek | 104 | 28% | Regular |
| 5-2-2-5 (alternating) | 183 | 50% | Shared |
| Week on/week off | 183 | 50% | Shared |
| 4 nights / 3 nights | 208 / 157 | 57% / 43% | Primary / Shared |
For a deeper look at which schedule might work for your family, read our guide on co-parenting schedules that actually work.
Care percentage and Family Tax Benefit
Care percentage doesn't just affect child support — it also determines eligibility for Family Tax Benefit (FTB) from Services Australia (Centrelink). If you have at least 35% care of a child, you can claim FTB for that child on a shared basis. Below 35%, only the primary carer can claim FTB for that child.
This is another reason why the 35% threshold (128 nights) is financially significant — it's the gateway to both shared child support treatment and shared FTB eligibility.
Getting help with care percentage disputes
If you and the other parent can't agree on care levels, these services can help:
- Family Relationship Advice Line: 1800 050 321
- Family Dispute Resolution (mediation): Available through Family Relationship Centres across Australia — it's free or low-cost, and you're generally required to attempt it before going to court
- Legal Aid: Free legal advice for eligible parents in every state and territory
