Judges determine child support based on 750 ILCS 5/505. Certain guidelines are set forth in that statute, and they are to be followed unless a judge determines that they are inappropriate. It has been my experience that the guidelines are used in nearly all cases and deviations are rare.
To calculate child support in accordance with the guidelines, the gross income of each parent must be determined. What sounds like a simple determination, it can become complicated when business income, maintenance (or what was long ago known as alimony), imputed income, support paid for other children, and more become part of the equation.
Also needed is a determination of the number of overnights each parent is allocated with the child or children. If a parent has at least 146 overnights (40%), it will likely reduce that parent’s typical child support obligation. The focus is not on overall time but instead on overnights.
Most family lawyers and judges use the Illinois Healthcare & Family Services calculator found at this link to determine child support: https://hfs.illinois.gov/childsupport/parents/childsupportestimator.html Still, even with the resulting number, child support may also include other child related expenses as well. Child care costs, extracurricular expenses, and school fees may be allocated as support obligations in addition to dollar amounts of child support.
