Care Percentage Calculator
Plan care nights from weekly, alternating-week or 14/28-night patterns with holiday changes, count them exactly over the real year, and see the official care rounding.
365 nights in the period
Holidays and other changes (0)
Changes are applied after the regular schedule, in order; where two overlap, the later one wins. Enter school holidays yourself — none are fetched or assumed.
Child 1: 365 nights
| With | Nights | Share of the period |
|---|---|---|
| Parent A | 156 | 42.7397% |
| Parent B | 209 | 57.2603% |
| Other / unassigned | 0 | 0.0000% |
Official care percentage — illustration
Rounded under s 54D (below 50% down, above 50% up): Parent A 42% (Shared care, cost 39%), Parent B 58% (Shared care, cost 61%).
Services Australia decides care from the actual care arrangement and evidence; a schedule is not a care determination and says nothing about custody or legal entitlement.
Calendar
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Set the first and last night of the period — a calendar year by default, with its real 365 or 366 nights.
- Describe the care: the same nights every week, alternating weeks, a repeating 7, 14 or 28-night pattern anchored on a date, date blocks, or night counts you already know. Every night goes to Parent A, Parent B or Other / unassigned — an unticked night is never quietly given to Parent B.
- Add holidays and one-off changes. Read the nights and shares, the month-by-month bars, and — when every night is assigned — the official care rounding. Export a CSV or send the nights to the Child Support Estimator.
How it works
Each night is named by the date it starts and generated as a date-only value, so daylight-saving changes cannot add or lose one. A repeating pattern assigns night d to position (d − anchor) mod length of the cycle; changes are then applied in order, the later one winning where two overlap, and every overlap is listed.
The schedule percentage is nights ÷ nights in the period, using the actual denominator. The official illustration rounds it under s 54D — below 50% down, above 50% up — and maps it to the care level and cost percentage with the same 2026 table the Child Support Estimator uses. A schedule is not a care determination and says nothing about custody.
Worked example
Monday, Wednesday and Friday in 2026. 2026 has 52 Mondays, 52 Wednesdays and 52 Fridays: 156 of 365 nights, 42.7397%. The official rounding takes that down to 42% — shared care, a 39% cost percentage. Thursdays alone would be 53 nights in 2026, which is why counting the real calendar beats weekdays × 52.
Frequently asked questions
Should I count days or nights?
Nights. Each night is named by the date it begins, which is how care is measured for child support.
How do holidays work?
Add each one as a change — from night, to night (inclusive), and with whom. Changes are applied after the regular pattern, and the later of two overlapping changes wins. School holidays are never fetched or assumed; you enter the ones that apply.
Why is no official percentage shown?
Because some nights are unassigned. The official rounding needs every night accounted for between the two parents; assign the rest or ask Services Australia how they count.
Related tools
- Child Support Estimator (Australia)
- Nights in Care Calculator
- Parenting Nights Per Year Calculator
- Custody Nights Percentage Calculator
- Pocket Money Savings Calculator
- Conception Date Calculator
Explore more in Family, Parenting & Custody.
Cite this tool
Zerdly. (2026). Care Percentage Calculator. Retrieved from https://www.zerdly.com/tools/care-percentage-calculator/
Tip: Enter any known values to calculate the remaining results.
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