Splitting parenting time exactly in half feels like it should zero out child support — but in most states, it doesn't. Child support formulas start from each parent's income, not just the calendar.
Why 50/50 custody usually still means a payment
Most state guideline formulas (the "income shares" model used by roughly 40 states) prorate the total cost of raising a child between both parents based on income share, then adjust for parenting time. If one parent earns significantly more, that income gap generally survives the custody adjustment — the higher earner typically still owes something, even at exactly equal overnights.
What actually changes at 50/50
What an equal schedule usually does is reduce the amount owed compared to a sole-custody arrangement, not eliminate it. Many states apply a parenting-time credit, a shared-custody worksheet, or a cross-multiplication formula once both parents cross a certain overnight threshold — see our joint custody guide for how that threshold varies by state.
When 50/50 custody really can mean $0
It's genuinely possible for the number to come out to zero (or close to it) when both parents have similar incomes and similar custody time — the formulas are designed so a truly equal case, income and time both, produces a small or no transfer payment. The bigger the income gap, the less true that becomes.
FAQ
Is there a state where 50/50 custody always means no child support?
No. Even states with generous shared-custody credits still factor in each parent's income — a large income gap will typically still produce a support obligation.
How do I find my exact number?
Use your state's calculator on this site, entering your actual overnight count — every calculator that has a custody adjustment applies your state's specific formula automatically.