Parenting Time Percentage Calculator
Calculate each parent's share of parenting time based on overnights or hours spent with the child per year. Commonly used in child support and custody agreements.
Total overnights must equal 365 (or 366 for leap year). You may enter one parent's nights and auto-fill the other.
Formulas Used
Overnights Method (most common in U.S. child support guidelines):
- Parent 1 % = (Parent 1 Overnights ÷ Total Overnights) × 100
- Parent 2 % = (Parent 2 Overnights ÷ Total Overnights) × 100
- Total Overnights = Parent 1 Overnights + Parent 2 Overnights (typically 365)
Hours Method:
- Parent 1 % of Shared Time = (Parent 1 Hours ÷ Total Parenting Hours) × 100
- Parent 2 % of Shared Time = (Parent 2 Hours ÷ Total Parenting Hours) × 100
- % of Full Year = (Parent Hours ÷ 8,760) × 100 [8,760 = 365 × 24]
Custody Thresholds (common U.S. standard):
- ≥ 50% each → Equal / 50-50 Parenting Time
- ≥ 60% one parent → Primary Custody
- 40–60% → Shared Parenting
Assumptions & References
- The overnights method is the standard used by most U.S. state child support guidelines (e.g., Colorado, Florida, Virginia, Washington) to determine parenting time percentages that affect child support calculations.
- A standard year is assumed to have 365 overnights (366 in a leap year). The calculator flags totals below 365 as unaccounted time.
- The hours method is used in states such as Arizona and Minnesota, and in situations where a parent's time does not include overnights (e.g., infants).
- One year = 8,760 hours (365 × 24). Hours exceeding this total are flagged as invalid.
- Parenting time percentages directly affect child support in many states under the Income Shares Model and Percentage of Income Model.
- A threshold of 40% parenting time (approximately 146 overnights) triggers shared-custody adjustments in many state guidelines.
- This tool does not constitute legal advice. Consult a licensed family law attorney or your state's child support guidelines for jurisdiction-specific rules.
- References: AAML (American Academy of Matrimonial Lawyers), state-specific child support worksheets, and the Uniform Interstate Family Support Act (UIFSA).