Calculating Your Net Monthly Income for Child Support Purposes

If you will be paying child support, it is important to properly calculate your net monthly income. Illinois courts will usually order you to pay a certain percentage of your net monthly income to whoever has primary residential custody of the child. Net income is defined as the total income from all sources, minus the following deductions:

1. Federal income tax (properly calculated withholding or estimated payments. Do not try to withhold more income than normal. You are required to pay a percentage of your tax refund as child support);

2 .State income tax (properly calculated withholding or estimated payments)

3.Social Security (FICA payments);

4.Mandatory retirement contributions required by law or as a condition of employment;

5.Union dues;

6.Dependent and individual health/hospitalization insurance premiums;

7.Court-ordered life insurance premiums to secure payment of court-ordered child support;

8.Child support payments and/or maintenance made pursuant to a support order for a previous case (Example: Bob was married to Anne and had one child, Zoe. During his divorce from Anne, Bob was ordered to pay child support for Zoe. Bob then marries Carrie and has another child, Yolanda. Bob and Carrie are now divorcing and Bob must calculate his net monthly income. Bob may deduct the child support he pays to Anne for Zoe when calculating his net income for the child support he will pay to Carrie for Yolanda.);

9.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.

This a basic way to calculate net monthly income using the permitted deductions outlined by the Illinois legislature. Illinois courts do not always need to follow the statute’s guidelines for support. The court may order more or less child support than a strict percentage calculation if there is a good reason for deviation. For example, people who earn a substantial amount of money each year may be able to have their child support obligation modified downward because paying a strict percentage of net monthly income would provide more money than the child’s reasonable needs.

Also, the time period for calculating net monthly income is important. If your earnings dramatically fluctuate from year to year, you may want to argue that the court should average several years of income to determine a more accurate and fair net monthly income.

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If you are looking for legal advice and representation with an Illinois divorce, schedule a consultation with experienced Chicago divorce attorney, Tanya Witt, at (312) 500-5400 or

Representing men and women in Chicago divorce and child custody cases.

This blog does not constitute legal advice. Please consult with an attorney regarding your specific case.