Illinois Child Support Calculator (2026)
In Illinois, child support is based on both parents' combined income and the number of children. The total is split between you based on how much each parent earns, and parenting time can change the amount. Use the free calculator below for an instant estimate.
Source: 750 ILCS 5/505 (Illinois Marriage and Dissolution of Marriage Act)
Calculate Your Illinois Child Support
Free estimate — official Illinois guidelines
Your income after taxes and required deductions
How Much Is Child Support in Illinois?
If you make $60,000 a year in Illinois, child support for 1 child is estimated at $903 per month ($10,836 per year). This assumes the other parent earns approximately $36,000/year. Actual amounts depend on both parents' incomes, custody time, and add-on expenses (child care, health insurance).
$1,000/week ($52,000/year): approximately $812/month for 1 child.
Illinois Child Support Estimates by Income (2026)
| Annual Income | 1 Child | 2 Children | 3 Children |
|---|---|---|---|
| $40,000/yr | $709/mo | $1,067/mo | $1,274/mo |
| $50,000/yr | $798/mo | $1,194/mo | $1,418/mo |
| $60,000/yr | $903/mo | $1,334/mo | $1,564/mo |
| $70,000/yr | $1,005/mo | $1,491/mo | $1,756/mo |
| $80,000/yr | $1,096/mo | $1,613/mo | $1,884/mo |
| $100,000/yr | $1,288/mo | $1,884/mo | $2,182/mo |
| $120,000/yr | $1,476/mo | $2,156/mo | $2,496/mo |
Estimates assume the other parent earns 60% of your income. Actual amounts vary. Compare all states →
How Child Support Is Calculated in Illinois
Factors That Affect Child Support in Illinois
Technical details and legal basis
Illinois uses the Income Shares model (750 ILCS 5/505 (Illinois Marriage and Dissolution of Marriage Act)) to calculate child support. This model combines both parents' incomes to determine the total obligation, then divides it proportionally based on each parent's share.
Important Notes for Illinois
- • Illinois switched from the Percentage of Income model to the Income Shares model effective July 1, 2017.
- • Child support is based on both parents' combined monthly net incomes using standardized tax deduction tables.
- • Net income is calculated using a standardized tax chart rather than actual taxes, ensuring consistency.
- • Illinois provides a shared parenting time adjustment when the non-custodial parent has 146 or more overnights per year (40%).
Example Calculation
Scenario: Parent A earns $5,000/month, Parent B earns $3,000/month, 2 children.
Step 1: Combined income: $8,000
Step 2: Parent A's share: $5,000 / $8,000 = 62.5%
Step 3: Look up basic obligation for $8,000 combined and 2 children.
Step 4: Multiply by Parent A's share (62.5%).
Adjustments for health insurance, child care, and parenting time may apply.
Key Facts: Child Support in Illinois
- Illinois uses the Income Shares model (since July 1, 2017), basing child support on both parents' combined monthly net incomes.
- Net income is calculated using standardized tax deduction tables rather than actual tax returns.
- The basic obligation for 1 child ranges from $207/month at $875 combined income to $3,463/month at $26,675 combined monthly net income (2025 HFS schedule).
- A shared parenting adjustment applies when the non-custodial parent has 146 or more overnights per year (40% of the time).
- The self-support reserve is 75% of the federal poverty level, approximately $998 per month (2026 FPL).
Illinois Child Support FAQ
How is child support calculated in Illinois?
How much is child support in Illinois?
How is net income calculated for Illinois child support?
Does shared parenting reduce child support in Illinois?
About This Calculator
Uses the official 750 ILCS 5/505 (Illinois Marriage and Dissolution of Marriage Act) (2025 guidelines). Last verified: 2026-05-31.
Disclaimer: Estimates only, not legal advice. Actual amounts are set by Illinois courts. Full disclaimer.
Methodology: Income Shares model per 750 ILCS 5/505 (Illinois Marriage and Dissolution of Marriage Act).