How do I calculate net income for child support?

Child support in Illinois is based on the net income of the non-custodial parent. Net income for purposes of child support may not be the same as your take-home pay. For example, most employers withhold a little too much money for taxes, which means the employee receives a tax return at the end of the year.

Your net income may also not be equal to the amount used to calculated yearly taxes on your tax return. Illinois allows for certain expenses to be deducted when calculating child support that the Federal government does not allow for tax purposes.

Statutory Definition of Net Income

Illinois law has a specific definition of net income, which you can read here: 750 ILCS 5/505(a)(3). It defines net income as the total of all income from all sources (including gifts), minus the following deductions:

  • Federal income tax (properly calculated withholding or estimated payments);
  • state income tax (properly calculated withholding or estimated payments);
  • Social Security payments (FICA payments);
  • mandatory retirement contributions required by law or as a condition of employment (optional 401K contributions are not deductible);
  • union dues;
  • dependent and individual health/hospitalization insurance premiums and life insurance premiums for life insurance ordered by the court to reasonably secure child support or support ordered pursuant to 750 ILCS 5/513, any such order to entail provisions on which the parties agree or, otherwise, in accordance with the limitations set forth in 750 ILCS 5/504(f)(1) and (2);
  • prior obligations of support or maintenance actually paid pursuant to a court order;
  • expenditures for repayment of debts that represent reasonable and necessary expenses for the production of income, medical expenditures necessary to preserve life or health, reasonable expenditures for the benefit of the child and the other parent, exclusive of gifts. The court shall reduce net income in determining the minimum amount of support to be ordered only for the period that such payments are due and shall enter an order containing provisions for its self-executing modification upon termination of such payment period; and
  • foster care payments paid by the Department of Children and Family Services for providing licensed foster care to a foster child.

Worksheet to Estimate Child Support

The Illinois Department of Healthcare and Family Services has created a worksheet to assist individuals predict the amount of child support they will be required to pay: Please note that this worksheet only contains the most common deductions and that you may be entitled by law to additional deductions. For case-specific questions, please call my office at 312-564-5373 for a free 30-minute telephone consultation.