This calculator determines the value of child support to be paid based on income, days the children spend in your custody, and other child-related expenses. Use this worksheet when one parent (or a third party) has primary physical custody of all of the children for whom support is being determined.Whether you're the dependent spouse or supporting spouse it's important to understand how spousal support or alimony is calculated in North Carolina. If you are curious about how your income will be calculated and used to make decisions regarding child support and alimony payments, learn more below. Worksheets to calculate guideline amounts of maintenance and child support. Optional tools to help with calculations are below. There isn't a specific formula for calculating alimony in North Carolina, and the calculator above should be considered a rough estimate. Understanding North Carolina Alimony Law. Unlike child support, there are no guidelines to determine the amount of alimony or spousal support in North Carolina.