Parenting Time & Overnights Percentage Calculator

How it works

Overnights = (nights per cycle ÷ cycle length) × year length (365.25 on average) + summer gain (weeks × (7 − regular nights per 7)) − weeks with A × regular nights per 7 ± holiday adjustment (+ ½ night per daytime block where credited); percentage = overnights ÷ year; threshold nights = threshold % × year, or the guideline's overnight count

Family courts and child-support formulas reduce a custody schedule to a single number — each parent's share of overnights in a year — because that share drives the support calculation, tax dependency claims and the label the arrangement carries. A repeating pattern is annualised, then adjusted for summer blocks and holiday splits that shift nights from the regular routine. Guidelines in most states apply a different, usually lower, support formula once the paying parent passes a threshold such as 35% (128 nights) or 40% (146 nights), which makes the difference between an every-other-weekend schedule at 14% and an extended weekend with a midweek overnight at 29% financially as well as personally significant. Pick a named schedule, enter overnights for any cycle length, type the pattern night by night (A or B for each night of one cycle), or enter a yearly count from a calendar. Summer weeks, holiday shifts and — for guidelines that credit them — daytime blocks are added on top. Compare the result with a threshold you enter, or with a state guideline from the list; the threshold table shows every listed guideline at once, and the build-up table shows where each parent's nights come from.

Worked example

A 2-2-5-5 rotation gives each parent 7 nights in 14 — about 183 overnights a year; adding two extra summer weeks and four net holiday nights lifts parent B to about 194 nights (53%) and parent A to 172 (47%), comfortably above a 35% shared-custody threshold for both. An every-other-weekend schedule alone would be 52 nights, 14%, and 76 nights short of the threshold. Adding one weeknight every week (EOW + weeknight, 4 nights in 14) brings parent B to 104 nights — enough for Florida's 73 or Ohio's 90, but still short of Maryland's 128.

Sources: Florida Statutes §61.30(11)(b) — time-sharing adjustment (20% of overnights) · Wisconsin Admin. Code DCF 150.035 — shared placement (25% / 92 days, equivalent care)

Frequently asked questions