Child Support Calculator by State (2026)

How the 2026 calculators work

There are two broad families of child support guidelines in the United States. The first is a percentage model, used by Texas and Wisconsin: the paying parent’s income (net resources in Texas, income available for child support in Wisconsin) is multiplied by a percentage that rises with the number of children. The second is the income-shares model, used by California, Florida, Illinois, Ohio, Indiana, Georgia, Michigan, New York, Pennsylvania, New Jersey, North Carolina, Virginia, Washington, Arizona, Massachusetts, Tennessee, Maryland, and Colorado: both parents’ incomes are combined, a basic obligation is set by a schedule or a percentage, and each parent is assigned a share of that obligation in proportion to income.

The differences that matter most are in the details. States define income differently, allow different deductions, treat overtime and bonuses differently, and update their schedules on different dates. A calculator that ignores those details can be off by hundreds of dollars a month. That is why this site does not publish a generic “national” child support formula. Each state page is built around the actual rule that courts in that state use.

The calculators also separate the basic obligation from the add-ons. Basic support is the core monthly amount for food, housing, clothing, and ordinary care. Add-ons can include work-related childcare, the children’s share of health insurance, uninsured medical expenses, and sometimes travel or extracurricular costs. Add-ons are usually split in proportion to income, but the exact rule varies by state. The guide to child support add-ons explains how each one is ordered and split.

What changes the number

1. The income definition

“Net income” is not the same as take-home pay. Texas starts with gross income and subtracts federal income tax, Social Security, Medicare, and specific deductions such as health insurance for the child, union dues, and mandatory retirement. California uses net disposable income under Family Code Section 4059. Ohio uses annual gross income in its schedule. Indiana uses weekly adjusted income. Georgia starts with adjusted gross income, which includes deductions for self-employment tax and prior support orders. Pennsylvania subtracts only the deductions listed in its rule: taxes, FICA, non-voluntary retirement, union dues, and alimony paid. The state page tells you which number to enter, and the guide to variable income covers overtime, bonuses, and self-employment profit.

2. Parenting time

Parenting time is not a simple discount. California’s formula uses the higher earner’s timeshare directly, so the result changes continuously as overnights move toward 50/50. Florida applies a 1.5× multiplier when each parent has at least 20% of the overnights, then compares each parent’s share. Illinois, Ohio, Indiana, Georgia, Michigan, and Pennsylvania use separate shared-parenting or parenting-time worksheets that this site does not reproduce. New York and Texas keep parenting time out of the formula entirely. If you have significant shared custody, use the official calculator linked on the state page. The guide to 50/50 custody and child support compares how the twenty states handle it.

3. Add-ons and deviations

Childcare, health insurance, and extraordinary medical or educational costs can be added to the basic obligation. Courts can also deviate from the guideline for reasons listed in state law, such as special needs, extraordinary expenses, or a parent’s travel costs. A guideline estimate is a starting point, not a ceiling.

Why state lines matter

Three questions the estimate cannot answer

First, it cannot tell you whether the other parent will agree with the income figure. Second, it cannot tell you how a judge will weigh the facts that are not in the formula, such as a child’s special needs or a parent’s travel costs. Third, it cannot tell you whether the order will be modified later. A guideline estimate is a snapshot of the basic obligation, not a forecast of the whole case.

The useful comparison is not which state pays more in the abstract. It is what the same facts produce under each state’s rule, and which assumptions drive the difference. The state pages show the formula and the exclusions next to the number so you can see both. The comparison of the twenty state guidelines goes deeper into each rule, and the guideline tables by state run the same facts through all twenty.

What these calculators do not do

If your situation includes shared custody, a child with special needs, a parent outside the state, a prior support order, or a significant income change, the basic estimate is not enough. Those facts can move the number in either direction, and the court has discretion that no calculator can reproduce.

Frequently asked questions

Sources for each state are listed on the state page and in the methodology. The site is updated when a state publishes a new schedule or changes its guideline; the last-updated date at the top of the page shows the most recent review.