How Much Is Child Support? Percentages, Formulas and a Calculator
Updated · By the Law Figures editors
General information, not legal advice. Laws differ by state and change, so check the sources below or ask a lawyer licensed in your state before you act. Legal disclaimer
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How much child support is depends on your state's formula, the parents' income and the number of children. Every state has to have guidelines, and a court must use them unless it explains why the amount would be unjust (42 U.S.C. § 667). In Texas, one child means 20% of the paying parent's monthly net resources; in New York, it's 17% of the parents' combined income, split by each parent's share.
| Children | Texas: share of paying parent's net resources | Texas, net under $1,000 a month | New York: share of combined parental income |
|---|---|---|---|
| 1 | 20% | 15% | 17% |
| 2 | 25% | 20% | 25% |
| 3 | 30% | 25% | 29% |
| 4 | 35% | 30% | 31% |
| 5 or more | 40% | 35% | 35% or more |
Texas sources: Family Code § 154.125(b) and (c). New York: Domestic Relations Law § 240(1-b)(b)(3). Both states cap the income these percentages apply to, and the court decides how much to add above the cap. We checked both statutes on November 7, 2026.
Run your own numbers
Pick the state, the number of children and the income figure the state uses. Texas looks at the paying parent's monthly net resources; New York uses both parents' yearly income.
Child support calculator
- Guideline percentage
- 20%
- Monthly support
- $800
Both states cap the income the percentage applies to, and courts can go above or below the guideline. Health insurance, child care and other add-ons are on top. Other states use different formulas.
With the defaults, a Texas parent with $4,000 a month in net resources and one child pays 20%, or $800 a month. Switch to New York: $80,000 and $40,000 make $120,000 combined, 17% of that is $20,400, and the paying parent's two-thirds share is $13,600 a year, about $1,133 a month.
How other states figure it
States use one of three kinds of formula:
- Income shares. The most common. The state's table gives the amount parents with your combined income would spend on children, and each parent pays a share in proportion to income. New York's method is close to this.
- Percentage of income. A share of only the paying parent's income, like Texas.
- Melson formula. A few states first set aside a basic amount for each parent's own needs.
Each state must review its guidelines at least every four years, so tables change. Use your own state's official worksheet or calculator for a real estimate.
What gets added on top
The basic amount is rarely the whole order. Courts commonly add:
- health insurance for the children, and how uninsured medical bills are split;
- child care costs so a parent can work or go to school;
- in some states, school or activity costs.
Time with each parent can also change the amount. Many states adjust support when parenting time is close to equal; Texas and New York handle it in their own ways.
Why your amount may differ
- Income isn't just salary. States count bonuses, self-employment income and sometimes money a parent could earn.
- Other children a parent supports can lower the amount.
- Income above the cap is up to the judge.
- The court can depart from the guideline if it explains why.
- An agreement between parents still needs the court's approval, and many states require it to show the guideline amount.