A court looks at the payer's gross income from all sources, less any mandatory deductions (income taxes, Social Security, health care, and mandatory union dues). The result is the payer's net income.
In most states, deductions for credit union payments, wage attachments, and so on are not subtracted when calculating net income. For example, John may make $2,000 per month, and his net income is $1,500 after income tax, Social Security, unemployment insurance benefits, and other government deductions. But the fact that $300 more is withheld to pay a credit union loan does not further reduce his net income for the court's purposes. The reason for this rule is that the law considers support payments a higher priority than other types of debts.
In some states the court may take into account the reasonable expenses incurred by the paying spouse for his or her own basic necessities of life (such as rent or mortgage, food, clothing, and health care). However, courts typically do not allow expenses such as school expenses, dining out, and entertainment to influence their support determination. The theory is that family support should come before these types of personal expenses. And, in a growing number of states, the expenses of the paying spouse are irrelevant.
If you are already paying child support for children from another marriage, some states allow you to deduct the amount of child support you pay for other children from your net income figure. If you are asked to complete a financial statement, be sure to include this expense.