Parenting Plan Calculator — All
50 States

Legal custody is the right to make major decisions about a child's upbringing — education, healthcare, religious instruction. Physical custody (also called residential custody) determines where the child primarily lives. Joint legal custody — where both parents share decision-making — is standard in most states today, even when one parent has primary physical custody. Sole legal custody is reserved for situations involving documented domestic violence, substance abuse, or demonstrated inability to co-parent. Physical custody splits are described by overnight percentages: 50/50 means equal overnights; 70/30 means one parent has the child 70% of nights.

Most states now have statutes or judicial presumptions favoring frequent and continuing contact with both parents — which in practice means courts frequently award 50/50 physical custody when both parents are fit and involved. States with explicit 50/50 presumptions include Arizona (A.R.S. § 25-403.02), Florida (F.S. § 61.13), and Kentucky (KRS § 403.270). Even in states without a statutory presumption, 50/50 schedules are common in uncontested divorces. The 'best interests of the child' standard remains the legal test — but that standard increasingly incorporates research showing benefits of both-parent involvement.

Child support is calculated using each state's formula, which typically incorporates both parents' incomes and the number of overnights each parent has. More overnights generally reduces the paying parent's support obligation because that parent bears more direct child-related costs. In California, the Dissomaster formula directly uses overnight percentages. In most states, crossing thresholds — like shifting from 70/30 to 50/50 — can change support by hundreds of dollars per month. This calculator shows exact overnight counts for common schedules so you can model the support implications.

Yes — a parenting plan becomes legally binding only when it is filed with and approved by a family court judge. Even if both parents agree completely, the agreement must be submitted as a proposed parenting plan or incorporated into a final divorce decree. Courts review parenting plans to ensure they serve the child's best interests, not just the parents' convenience. Once approved, the parenting plan is a court order — violations can result in contempt of court. Most courts accept agreed plans without a hearing unless something raises a concern.

To modify a court-approved parenting plan, you generally must show a 'substantial change in circumstances' since the order was entered — such as a parent relocating, a significant change in a child's needs, or documented evidence that the current schedule isn't working. Both parents can agree to a modification (the easiest path), which is then submitted for court approval. Contested modifications require filing a motion, potentially a hearing, and sometimes a custody evaluation. If both parents agree to temporary schedule adjustments without changing the legal order, that's generally allowed — but informal changes don't modify the underlying court order.