Child support in Naperville: how it is calculated
Child support in Naperville is set by Illinois's statewide guidelines — DuPage County courts apply the same table as every other county. Here is the calculation, with the statute it comes from.
Where a Naperville case goes
A Naperville case is filed in the Illinois court for DuPage County, which applies the state guideline below. Local practice affects timing and paperwork, not the guideline amount. Naperville has about 153,124 residents (Census Bureau, 2024 estimate).
Open the full Illinois child support calculator → — same formula, with every input, the statute (750 ILCS 5/505(a)(1), (3.3a), (3.5); HFS Income Shares Schedule of Basic Child Support Obligations (eff. Mar. 20, 2026)) and the date it was last checked.
Formula
Schedule by combined net income ($50–$27,350/mo), payer owes income share; minimum $40/mo
Type
Income-shares model
Does Naperville have its own rule?
No. 750 ILCS 5/505(a)(1), (3.3a), (3.5); HFS Income Shares Schedule of Basic Child Support Obligations (eff. Mar. 20, 2026) applies across Illinois, so a case from Naperville is decided by the same numbers as one filed anywhere else in the state. What changes locally is the courthouse, the clerk's procedure and how long the docket takes — not the amount.
What the statute says
750 ILCS 5/505(a)(1), (3.3a), (3.5); HFS Income Shares Schedule of Basic Child Support Obligations (eff. Mar. 20, 2026) — Illinois income shares schedule of basic child support obligations (combined monthly net income). Illinois uses the parents' combined monthly NET income (gross income less federal and state taxes and FICA, using the HFS standardized or individualized net income conversion). The Income Shares Schedule of Basic Child Support Obligations published by the Department of Healthcare and Family Services under 750 ILCS 5/505(a)(1), most recently revised effective March 20, 2026, lists $50-wide income brackets from $25.00-$74.99 up to $27,325.00-$27,374.99; each bracket is stored here at its midpoint ($50, $100, ... $27,350) so that the nearest row is the bracket that contains the income. For combined net income above the schedule, § 505(a)(3.5) lets the court use its discretion but never below the top bracket, so no percentage is added. Under § 505(a)(3.3a) an obligor at or below 75% of the federal poverty guideline owes a presumptive minimum of $40 per month per child (maximum $120), shown here as a flat $40 floor. Child care, health insurance premiums and extraordinary expenses are added on top, and the shared-physical-care formula applies at 146 or more overnights.
Last checked 2026-09-11; figures pending final verification against the current statute or schedule. Read the source →
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