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.Information about child support, filing, court process, enforcement and more. Contents. Use our child support calculator to provide an estimate of the child support payments the court may order you to pay in NC.. Call us today at 919-829-1006. Monthly Child Support Calculator. This calculator provides an estimate for a single source of income. North Carolina calculates how much child support will be largely based on income and the number of children involved. The amount of child support to be paid is based upon the NC Child Support Guidelines. In any state, get an idea of how much child support you might pay or have to receive after your divorce. States generally use one of three models to determine the base child support amount due.