A custody schedule calculator computes the annual overnight percentage for each parent based on a weekly custody schedule. The overnight percentage is a key input in child support calculations in most states.
Quick Schedule Presets
Or build a custom schedule below
Weekly Schedule — Week 1
Click each day to assign to Parent A or Parent B (click again to toggle)
Weekly Schedule — Week 2 (if alternating)
Schedule Name
Child Support Reference
Parenting time calculations are for reference only. Child support formulas vary by state. Consult a family law attorney for your specific situation.
How to Use the Custody Schedule Calculator
This custody schedule calculator helps parents and attorneys calculate the exact overnight percentage for each parent under a proposed or existing custody arrangement. Overnight percentages matter because most states use them as a key variable in calculating child support.
Step 1: Select a Preset or Build Custom
Start with a common schedule preset to see how typical arrangements work, then customize using the day selector. The every-other-weekend schedule (the classic non-custodial parent arrangement) results in approximately 14% overnights per year. Equal 50/50 parenting results in 50% each. Most real custody orders fall somewhere between these extremes.
Step 2: Assign Days for Two-Week Cycle
Many custody schedules repeat on a two-week cycle. Week 1 and Week 2 may be different — for example, a parent might have the child Monday–Friday in Week 1 and only the weekend in Week 2. If your schedule is a simple weekly repeating pattern, you can leave Week 2 blank and the calculator will use Week 1's pattern for both weeks.
Understanding Overnight Percentages
An "overnight" in child support calculations is typically defined as a night during which the child sleeps in the parent's home. Courts count overnights per year, then convert to a percentage. Most states with income shares models (used by about 40 states) provide a reduction in child support when the non-custodial parent has the child 40%+ of overnight time (about 146 nights/year).
Common Schedule Names
Courts and mediators use standard names for common schedules: "every other weekend" (EOW), "2-2-3" (alternating 2, 2, and 3-day periods), "alternating weeks," and "5-2-2-5." Knowing the name of your proposed schedule helps when discussing options with your attorney or mediator.
Frequently Asked Questions
What is the standard custody schedule?
The most common schedule is every other weekend (EOW), where the non-custodial parent has the child Friday–Sunday every other week — about 14% of overnight time. Equal (50/50) custody is increasingly common and gives both parents equal time.
How does parenting time affect child support?
In most states, the non-custodial parent's child support obligation decreases as their parenting time increases. Many states provide a discount when the non-custodial parent has the child 40% or more of overnight time (about 146+ nights/year).
What does 50/50 custody look like in practice?
Common 50/50 schedules include: alternating weeks (7 days each), 2-2-3 rotation (2 days, 2 days, 3 days alternating), or 3-4-4-3. All result in approximately 182–183 overnights each per year.
What is supervised visitation?
Supervised visitation requires a third party to be present during parent-child contact, typically ordered by the court when there are safety concerns. It is a temporary measure and can be modified as circumstances change.
Is this tool free?
Yes, completely free with no signup required. All calculations run locally in your browser.