NC DVPO How North Carolina calculates child support
North Carolina uses the income-shares model: a child should receive the same share of the parents' combined income they would have if the parents lived together. Both incomes go on the worksheet, a basic obligation is read from the state schedule, and certain expenses are added and divided in proportion to income.
The three worksheets
- Worksheet A — primary custody: one parent has the child 243+ nights/year; the other pays their income share.
- Worksheet B — shared custody: each parent has the child 123+ nights/year; the basic obligation is multiplied by 1.5 and adjusted for time with each parent.
- Worksheet C — split custody: each parent has primary custody of at least one of the children.
The 123-overnight rule
The number of overnights is decisive: at 123 overnights a year the case shifts from Worksheet A to the shared-custody Worksheet B, which usually lowers a higher earner's obligation — one of the most important numbers in any North Carolina support case.
What's added to the basic obligation
Work-related child care, the child's health-insurance premium, and certain extraordinary expenses (special-needs schooling, travel for visitation) are added and prorated by income.
Modifying support
An order at least three years old can be modified if the guideline amount differs by 15% or more; otherwise you generally must show a substantial change in circumstances.
Free child support calculator
Estimate support under Worksheet A, B, or C using the official 2023 schedule — with help on every field and a Worksheet A-vs-B comparison.
Open the Child Support CalculatorFrequently asked questions
What is the 123-overnight rule in North Carolina child support?
If the child spends at least 123 nights a year with each parent, the case uses the shared-custody Worksheet B (basic obligation × 1.5, adjusted for time) instead of the primary-custody Worksheet A.
How is child support calculated in North Carolina?
Using the income-shares model: both parents' incomes, a basic obligation from the state schedule, plus child care, health insurance, and extraordinary expenses prorated by income.
When can child support be modified in North Carolina?
An order three or more years old can be changed if the guideline amount differs by 15% or more; otherwise you generally must show a substantial change in circumstances.
Is there a free North Carolina child support calculator?
Yes — this site has a full calculator using the official 2023 North Carolina schedule for Worksheets A, B, and C.