Custody Percentage: How Courts Actually Count Overnights
Parenting time percentages come from counting overnights across a full repeating cycle — not hours, not days, not how it feels. Here is the method, and the four mistakes that produce a wrong number.
Ask two parents what their split is and you will often get two different answers for the same schedule. That happens because they are counting different things.
Most courts and state child-support worksheets count overnights. The parent the child sleeps with that night gets credit for the night. Daytime visits, dinner visits, and school hours generally do not add to the percentage on their own.
The method, step by step
1. Identify the repeating cycle — one week, two weeks, or four weeks. 2. Count the number of nights each parent has in one full cycle. 3. Divide each parent's nights by the total nights in the cycle. 4. Multiply by 365 if you need an annual overnight count.
A 2-2-3 rotation runs on a 14-night cycle: 7 nights each, 50%. A 4-3 runs on a 7-night cycle: 4 and 3, so 57% and 43%. Every other weekend plus a midweek overnight is 4 nights per 14 — about 29%.
The four mistakes that skew the number
Counting days instead of nights. A Saturday where the child is with you 10am to 8pm is a full day and zero overnights. Real time, no percentage credit.
Ignoring the holiday and summer schedule. Holiday overrides can move ten or more nights a year. If your order has an alternating holiday clause and a summer block, the annual number is not the same as the base rotation.
Averaging a month instead of a cycle. A calendar month does not divide evenly into a two-week rotation, so a month-based count is almost always off.
Counting an entitlement you do not exercise. Some states count ordered time; others look at actual exercised time when a party raises it. If your practice differs from your order, keep records — that record is the evidence.
Where the percentage changes money
In income-shares states with a shared-parenting adjustment, crossing a threshold — often somewhere between 25% and 35% of overnights, and in some states higher — changes the support calculation. In a few states the change is a cliff rather than a slope, which is why the exact number matters. Check your state's model with the child support estimator.
Prove it, do not assert it
If parenting time is contested, an assertion is worth little and a contemporaneous record is worth a lot. Log each exchange as it happens, with times, and export the history when you need it. See what courts accept as evidence.
Run your own pattern through the custody percentage calculator to get a defensible figure.
The CustodyTrac Team
Written for parents building two-home families.