Custody Nights Percentage Calculator
Work out each parent's custody nights and percentage split from a shared care schedule with this free calculator, right in your browser.
Enter Values
Minimum 0
Minimum 0
How to use this calculator
- Enter the nights per year with each parent.
- Read each parent's percentage.
How it works
Each parent's percentage = their nights ÷ total nights × 100.
Worked example
104 vs 261 nights. ≈ 28.5% / 71.5%.
Common mistakes
- Counting days instead of overnight stays — care is usually measured in nights.
- Assuming this defines legal care — definitions vary by purpose.
Frequently asked questions
How is custody percentage calculated?
It is the nights a child spends with one parent divided by the total nights in the period, as a percentage. 146 of 365 nights is about 40%.
Why do custody nights matter?
Many child-support formulas and parenting orders are tied to the share of nights, so the percentage affects arrangements and payments. It is a guide, not legal advice.
Is this legal or child-support advice?
No — it's a simple share of overnights. Care percentages for legal or support purposes can be defined differently; seek proper advice.
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- Parenting Nights Per Year Calculator
- Child Support Estimator (Australia)
- Conception Date Calculator
Explore more in Family, Parenting & Custody.
Cite this tool
Zerdly. (2026). Custody Nights Percentage Calculator. Retrieved from https://www.zerdly.com/tools/custody-nights-percentage-calculator/
Tip: Enter any known values to calculate the remaining results.
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