Child Expense Split Calculator — United States

Most state child support guidelines divide extraordinary child expenses (also called add-ons) in proportion to each parent's income. Some states use a strict 50/50 split, but income-proportionate sharing is more common. Extraordinary expenses typically include work-related childcare, unreimbursed medical costs, and private school tuition when appropriate.

Extraordinary expenses are child-related costs not covered by base child support: work-related daycare, uncovered medical and dental expenses, prescription medication, mental health therapy, tutoring, private school tuition, sports equipment, and extracurricular activity fees. Each state's guidelines define what qualifies.

Yes. Parents can agree to any sharing arrangement in a parenting plan or separation agreement, including 50/50. Courts will generally approve an agreement that serves the child's best interests. An income-proportionate split is the default if parents cannot agree.