How Illinois Calculates Child Support

Illinois uses the Income Shares model. Both parents' net incomes are combined to determine the basic support obligation. Each parent then contributes their proportional share based on their percentage of the combined income. Shared parenting adjustments apply when a parent has 146+ overnights (40%).

Monthly Income

Parent 1

Gross Monthly Income

Before taxes

Net Monthly Income

After standardized taxes (auto-calculated if left blank)

Parent 2

Gross Monthly Income

Before taxes

Net Monthly Income

After standardized taxes (auto-calculated if left blank)

Combined Net Monthly Income $0

Children & Parenting Time

Number of Children

Primary Custodial Parent

Shared parenting (both parents have 40%+ overnights)

Additional Expenses

Monthly Childcare Costs

Work-related childcare

Monthly Health Insurance (children)

Premium for children only

Results

Guideline Child Support

Monthly Child Support $0

Annual Amount $0

Payor -

Basic Support Obligation $0

Payor's Income Share 0%

Important Disclaimer

This calculator provides estimates only based on 750 ILCS 5/505 guidelines. Actual amounts may differ based on judicial discretion, deviations, and specific case factors. Low-income provisions may apply if income is below 75% of federal poverty guidelines. This is not legal advice. Consult an Illinois family law attorney for accurate guidance.