Illinois child support calculator (2026 guidelines)
Illinois guidelines effective March 20, 2026. Change state
For 2 children, with Parent A earning $60,000 and Parent B $40,000, Illinois's guideline amount is $1,142 a month (Parent A pays Parent B).
Illinois uses the income shares model; its current guidelines took effect March 20, 2026.
This is the guideline amount, not a court order.
Calculate your Illinois guideline amount
Guideline child support
Choose your state and enter both incomes to see the guideline amount.
Illinois child support at a glance
| Children | $30,000 | $50,000 | $75,000 | $100,000 |
|---|---|---|---|---|
| 1 child | $456 | $661 | $870 | $1,084 |
| 2 children | $688 | $986 | $1,292 | $1,605 |
| 3 children | $825 | $1,169 | $1,522 | $1,886 |
| 4 children | $921 | $1,306 | $1,700 | $2,107 |
| 5 children | $1,013 | $1,436 | $1,870 | $2,317 |
How Illinois calculates child support
Illinois uses the income shares model: the schedule gives the support for the parents' combined net income, and the paying parent pays their percentage share.
Net income comes from the state's standardized gross-to-net table, which differs for the parent with most of the parenting time. Support paid for other children is then deducted.
When each parent has at least 146 overnights a year, the basic obligation is multiplied by one and a half, shared by income and offset by each parent's time.
When the paying parent's gross income is at or below the state's low-income line, the presumed order is $40 a month per child, up to $120 shared equally among all of that parent's children. A parent with no income has a presumed order of zero.
The children's health insurance premium is shared by net income. Child care and school costs are ordered separately at the court's discretion.
Support paid under orders for other children is deducted from net income; for other children without an order, a court can deduct up to 75% of the guideline amount for them.
Above $27,325 of combined net income a month the court decides, but support is at least the amount at the top of the schedule.
Income shares and parenting-time shares are rounded to a hundredth of a percent, and each worksheet line is worked to the cent.
Parenting time in Illinois
When each parent has at least 146 overnights a year, the basic obligation is multiplied by one and a half, shared by income and offset by each parent's time.
| Overnights with Parent A | Guideline amount | Who pays |
|---|---|---|
| 0 | $1,142 a month | Parent A pays Parent B |
| 52 | $1,142 a month | Parent A pays Parent B |
| 104 | $1,142 a month | Parent A pays Parent B |
| 128 | $1,142 a month | Parent A pays Parent B |
| 182 (about equal) | $260 a month | Parent A pays Parent B |
Low and high incomes in Illinois
For 2 children with Parent B earning $40,000, the guideline amount is about $475 a month when Parent A earns $20,000 a year and about $3,018 a month when Parent A earns $250,000.
When the paying parent's gross income is at or below the state's low-income line, the presumed order is $40 a month per child, up to $120 shared equally among all of that parent's children. A parent with no income has a presumed order of zero.
Above $27,325 of combined net income a month the court decides, but support is at least the amount at the top of the schedule.
Child support by number of children in Illinois
- 1 child$761 a month
- 2 children$1,142 a month
- 3 children$1,360 a month
- 4 children$1,519 a month
- 5 children$1,670 a month
Parent A earns $60,000, Parent B $40,000; the children live mostly with Parent B.
Official sources and verification
- Law: 750 ILCS 5/505
- Illinois child support guidelines
- Support Obligation Worksheet (HFS)
- Official Illinois child support calculator
- Illinois Department of Healthcare and Family Services, Child Support Services
- Changing a Illinois child support order
Guidelines effective March 20, 2026. Verified against the official Illinois sources on October 6, 2026. How we calculate →
Frequently asked questions
How is child support calculated in Illinois?
Illinois uses the income shares model: the schedule gives the support for the parents' combined net income, and the paying parent pays their percentage share. Net income comes from the state's standardized gross-to-net table, which differs for the parent with most of the parenting time. Support paid for other children is then deducted.
What is the child support for one child in Illinois on $50,000?
If Parent A earns $50,000 a year, Parent B earns $40,000 and the child lives mostly with Parent B, Illinois's guideline amount for one child is about $661 a month (Parent A pays Parent B). Courts can deviate from the guideline amount.
Does 50/50 custody mean no child support in Illinois?
Not necessarily. With about equal parenting time, 2 children, Parent A earning $60,000 and Parent B $40,000, the guideline amount is about $260 a month (Parent A pays Parent B). When each parent has at least 146 overnights a year, the basic obligation is multiplied by one and a half, shared by income and offset by each parent's time.
What is the minimum child support in Illinois?
When the paying parent's gross income is at or below the state's low-income line, the presumed order is $40 a month per child, up to $120 shared equally among all of that parent's children. A parent with no income has a presumed order of zero.
When does child support end in Illinois?
Support ends at 18, or for a high school student at graduation or 19, whichever is earlier. Courts may order college expenses and support for an adult child with a disability.