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: