In California, in the absence of an agreement providing otherwise, child support is calculated by using a “guideline” formula, which takes into consideration the respective incomes of each parent, the percentage of time the child has with each parent, and various other factors that affect an individual’s income or taxes. This formula is based on an assumption that a certain percentage of the family’s total income is spent on the children. When a parent’s share of the family income is higher than his or her share of the time with the children, child support is used to shift income to the other parent. In most cases, the guideline amount is followed by the court; there can be unusual circumstances that warrant a change from the guideline amount.
Because the mathematical formula is complex, attorneys and courts use computer programs, such as DissoMaster and SupporTax, to calculate guideline support. Individuals can use the statewide guideline calculator online, located here: http://www.childsup.ca.gov/Resources/CalculateChildSupport.aspx. Be aware that even small changes in the input numbers can create significant differences in the guideline support amount, and that different programs generate slightly different results. The actual amount of support to be paid in any case is ultimately determined by the judge.
The base monthly support is for living expenses, such as housing, clothing, food, etc., for the time the children are in the care of one parent. If a parent has the children 30% of the time, she or he is expected to pay 30% of these expenses. Child support agreements or orders often have “add-ons” for additional expenses such as uncovered health care expenses or child care.