Child Support Care Percentage Estimator

In child support calculations — particularly under the Australian Services Australia framework — the percentage of care each parent provides is a pivotal number. It determines whether a parent is classified as having regular care, shared care, or primary care, and directly drives the cost offset applied to their income-based obligation. Even small differences in the care percentage can shift a parent from one band to another, sometimes meaningfully changing the monthly payment. This Child Support Care Percentage Estimator helps parents accurately compute their care percentage before applying it to a full child support assessment.

What counts as care time? Under Services Australia's rules, a night of care occurs whenever the child sleeps at a parent's home. However, the formula also recognises daytime-only care by counting each such day as half a night equivalent. School holiday time where children stay with a parent (even if they return before the evening) may also be counted as fractional care time depending on the circumstances.

Care bands and their significance: Services Australia divides care percentages into five bands that determine the cost offset in the child support formula:
• Below 14% — No cost offset. The parent is not considered a regular carer.
• 14% to 34% — Regular care. A fixed 24% cost offset applies.
• 35% to 52% — Shared care (lower range). The offset increases from 25% to 42%.
• 53% to 64% — Shared care (upper range). Offset increases from 43% to 50%.
• 65% and above — Primary care. Offset increases beyond 50%, with additional cost offsets applying for each percentage point above 65%.

Why precision matters: Being classified as having 34% care versus 35% care triggers different offset percentages. Similarly, moving from 65% to 66% care increases the offset further. Parents who share care roughly equally — near the 50/50 mark — should calculate carefully because the bands determine substantial financial differences.

Disputed care: When parents disagree on the actual care percentage, Services Australia makes a determination based on the parenting order or a pattern-of-care assessment. Keeping records of actual overnight stays (e.g., in a shared calendar or diary) provides evidence if the arrangement is later disputed.

This estimator is designed around the Australian system but the concept of translating overnight nights and daytime contacts into a percentage is universally useful for any jurisdiction that recognises parenting time as a factor in child support calculations. U.S. parents can use the percentage directly in the main Child Support Calculator on this site.