Illinois Child Support Calculator
Illinois adopted the income shares model effective July 1, 2017, replacing the prior flat-percentage model. Combined net income of both parents is used to look up base support obligation from a schedule. Each parent pays a proportional share. Parenting-time adjustment applies when each parent has the child at least 146 overnights.
How Illinois Calculates Support
Model:Income Shares (schedule-based; changed from flat percentage model in 2017)
Income Basis:combined net income (both parents)
Formula:Illinois adopted the income shares model effective July 1, 2017, replacing the prior flat-percentage model. Combined net income of both parents is used to look up base support obligation from a schedule. Each parent pays a proportional share. Parenting-time adjustment applies when each parent has the child at least 146 overnights.
What You'll Need
- Number Of Children On Order*
- Parent A Net Income*
- Parent B Net Income*
- Parenting Time Overnights*
- Other Support Obligations
* Required fields — optional items shown in gray