Illinois child support calculator
You can see how much child support is likely to be in Illinois before you talk to a lawyer or go to court, because the state uses a set formula based on both parents' incomes. Put in each parent's income before tax and we'll work it out with the state's 2026 tables.
Illinois rules change on January 1, 2027. Shared care will start at 110 nights a year instead of 146, and the minimum order will cover more low-income parents. This estimate uses today's rules.
$0.00 a month
Put in both parents' incomes to see an estimate.
Tell us about your situation and where you are. We'll follow up about the next step.
Illinois turns gross income into net income with a standard tax table, not your actual tax return. If you and the other parent agree, or a judge decides, your actual taxes can be used instead, and the result can change. Spousal maintenance, Social Security benefits paid for the children and income a judge might impute aren't included. It also doesn't cover children who live mostly with different parents, where Illinois works out each side separately, or the federal child care tax credit, which comes off child care costs.
How child support is calculated in Illinois
Illinois looks at both parents' incomes. Each parent's gross income is turned into net income with the state's standard tax table, and the two are added together. The income shares schedule then sets what parents with that combined income would spend on their children, and each of you owes your share of it. The parent the children live with most keeps their share for the children, and the other parent pays theirs.
| Combined net income a month | 1 child | 2 children | 3 children |
|---|---|---|---|
| $2,000 | $461 | $702 | $848 |
| $4,000 | $921 | $1,378 | $1,656 |
| $6,000 | $1,211 | $1,808 | $2,142 |
| $8,000 | $1,444 | $2,137 | $2,507 |
| $10,000 | $1,686 | $2,499 | $2,938 |
| $15,000 | $2,269 | $3,302 | $3,806 |
| $20,000 | $2,784 | $4,119 | $4,836 |
The 2026 schedule runs to $27,374.99 of combined net income a month for up to 6 children. Above that, the top amount ($3,547 for one child) is the least a judge can order. If each parent has the children at least 146 nights a year, the schedule amount is multiplied by 1.5, each parent's part is multiplied by the other parent's share of the nights, and the parent who owes more pays the difference. These are the rules through December 31, 2026. From January 1, 2027, Illinois counts shared care from 110 nights a year, changes the formula for a parent with 110 to 145 nights, and raises the income limit for the $40-a-child minimum to $1,330.00 a month. This estimate doesn't use those rules yet, so if your order will be set in 2027 or later, ask a family law attorney how they apply to you.
If the paying parent earns $997.50 or less before tax a month (75% of the 2026 federal poverty guideline for one person), Illinois presumes $40 a month per child, and $120 at most across all of that parent's children. The children's health insurance premium is split by income share and added to support. Child care is split the same way but shown on its own, because a judge decides whether to order it.
When a judge can order more or less support
A judge starts from the guideline amount and presumes it's right. These can still change what's ordered:
- The child's needs. Extraordinary medical costs, or special medical, physical or developmental needs. To order more or less for reasons like these, a judge has to explain in writing why the guideline amount would be unfair.
- Each parent's resources. What each parent has and needs, and the life the child would have had.
- Income a parent could earn. If a parent chooses not to work or works less, a judge can use what they could earn, but only after a hearing or if both parents agree.
- Actual taxes. With both parents' agreement or a judge's decision, actual taxes replace the standard table.
- Extra costs. Medical bills insurance doesn't cover, and school or activity costs beyond the usual.
- Net income above $27,374.99 a month. The judge decides how much more the children need.
A judge won't treat coverage as reasonable if it costs the parent who provides it more than 5% of their gross income, and a parent with net income under $1,768.90 a month usually can't be ordered to pay toward private coverage.
Questions parents ask about Illinois child support
How much is child support in Illinois?
It depends on both parents' incomes and the number of children. If your combined net income is $6,000 a month and the paying parent earns 60% of it, the 2026 schedule sets $1,808 for two children and the paying parent owes $1,084.80 a month. The children's health insurance is split on top, and a parent with very low income is presumed to owe $40 a month per child.
What percentage of income is child support in Illinois?
There's no single percentage. Illinois sets an amount for the parents' combined net income, and the share falls as income rises: for one child it's 23.05% of $2,000 a month and 16.86% of $10,000. The paying parent owes their own share of that amount.
How does 50/50 custody affect child support in Illinois?
Through December 31, 2026, once each parent has the children at least 146 nights a year, Illinois multiplies the schedule amount by 1.5, credits each parent for the time the children spend with the other, and the parent who owes more pays the difference. With unequal incomes, support usually shrinks but doesn't disappear. A parent earning 60% of $6,000 combined net income owes $1,084.80 a month for two children with fewer than 146 nights, $542.40 with 146 and $275.00 with 182. From January 1, 2027, Illinois counts shared care from 110 nights a year, with a smaller credit for 110 to 145 nights.
What is the minimum child support in Illinois?
Through December 31, 2026, when the paying parent's gross income is $997.50 a month or less, Illinois presumes $40 a month per child, and $120 at most across all of that parent's children. A judge can order a different amount. A parent with no income, or who can't work because of a medically proven disability, incarceration or institutionalization, is presumed to owe nothing. From January 1, 2027, that limit rises to 100% of the poverty guideline, $1,330.00 a month at the 2026 figure.
Is there a maximum child support amount in Illinois?
No. When the parents' combined net income is above $27,374.99 a month, where the schedule ends, the top amount ($3,547 for one child, $5,210 for two) is the least a judge can order, and the judge decides how much more the children need.
Can you modify child support in Illinois?
Yes. Either parent can ask the court to change the order when circumstances have changed substantially. If a parent gets child support services from the Department of Healthcare and Family Services, the order can also be changed once 36 months have passed since it was entered or last changed, if the guideline amount now differs from it by at least 20% and at least $10 a month, unless the current amount came from a deviation that still applies. A change only applies to payments due after the other parent is notified of the request.
Where the numbers come from
- 750 ILCS 5/505, the Illinois child support guidelines
- The 2026 Illinois Schedule of Basic Obligations, from the Department of Healthcare and Family Services
- The 2026 Gross to Net Income Conversion Table, which sets the standard tax amounts
- The 2026 federal poverty guidelines, which set the minimum order and health insurance limits
- Senate Bill 3524, the law that changes shared care and the minimum order on January 1, 2027
- The state's child support estimator, run by the Department of Healthcare and Family Services
Checked September 29, 2026. Illinois updates both tables every year, and the current ones took effect March 20, 2026.
Talk it through with an Illinois family law attorney
A family law attorney can tell you what a judge is likely to order in your situation, and whether any of these adjustments apply to you.
Browse Illinois law firms