Parenting time, custody labels, and the percentage used in a child-support calculation describe related but different things. A label such as “joint custody” does not by itself establish a 50 percent timeshare.

Legal custody and physical custody

Legal custody concerns decisions about a child’s health, education, and welfare. Physical custody concerns the child’s care and living arrangements. The actual order explains each parent’s rights and responsibilities; its schedule may be more informative than its short label.

Timeshare in support calculations

Family Code section 4055 uses the approximate percentage of time the higher earner has or will have primary physical responsibility for the children, compared with the other parent. Determining that percentage can require more than counting overnights.

Review the regular schedule, holidays, school breaks, exchanges, and who has primary responsibility during the relevant periods. A five-day/two-day shorthand may conceal partial days and exceptions. Use a consistent period and avoid counting the same time twice.

Labels do not replace the facts

Joint physical custody need not mean an exactly equal schedule. Conversely, a support calculation does not itself change the parenting order. If the schedule or actual arrangements change, evaluate the support and custody issues separately.

See Visitation, DissoMaster, and XSpouse for related terms and calculation tools.

Source: Family Code section 4055, reproduced in the linked authority page. Reviewed October 23, 2026.