Illinois · STATE-SPECIFIC WORKFLOW

Illinois support worksheet.

Enter both parties’ countable income and the adjustments relevant to this state. The Illinois calculation uses the state’s income definition and the specific formula fields below.

Illinois income shares worksheet; standardized or individualized tax determination. 750 ILCS 5/505(a)

Independent estimate: This is not an official court calculation, a certified court form, or legal advice. Courts may order more or less. A PDF can still be edited; this site does not certify authenticity or guarantee court acceptance.

Illinois financial worksheet

Complete Party A and Party B, then the state formula fields.

State for this worksheet

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IllinoisLimited base calculation

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Illinois worksheet output

Income reconciliation, calculation, sources, and PDF.

Ready when you are

Complete both parties’ financial accounting to review your state-specific worksheet.

Amounts are calculated in your browser. No account or upload is required. PDF/print is the only report format.

Illinois requirements and review scope

Illinois income shares worksheet; standardized or individualized tax determination. Use 750 ILCS 5/505(a) to determine the amounts counted for each party.
Wages, dividends, interest, business earnings, and other countable income are added separately for each party. Enter each dollar once; do not repeat business profit as an owner distribution.
General asset balances, loan balances, and household spending are not collected in this support-calculation workflow. Enter countable earnings from assets. A separate court financial affidavit may require additional disclosures.
Business and rental deductions must be expenses allowed for support, which can differ from tax-return deductions. Do not deduct personal living expenses as business expenses.
This worksheet needs state-permitted tax and other deductions. Enter the guideline tax deduction, not take-home pay or every deduction shown on a pay stub. Automatic tax preparation is not provided.
Uses the Illinois HFS 2026 Income Shares Schedule of Basic Child Support Obligations based on net income, effective March 20, 2026.
The HFS income-shares page states Illinois annually updates both the Gross to Net Income Conversion Table and the Income Shares Schedule, and the schedule was most recently revised effective March 20, 2026.
This base module allocates the schedule obligation by each parent’s share of combined monthly net income.
Standardized gross-to-net conversion, health insurance, child care, extracurricular expenses, shared physical care, multi-family adjustments and deviations require the full Illinois worksheet.
For combined monthly net income above the last encoded HFS schedule range, this module uses the last schedule amount and flags the case for review.

The available formula is a limited base calculation. Full parity with every line of the official worksheet, custody arrangement, tax computation, credit, and discretionary adjustment has not been verified. Review the stated limitations and the official sources.

Read the Illinois guideline guide · Methodology and limitations · 50-state worksheet review