Child support questions

How is child support calculated?

How to use this page: review the guidance below, enter the requested information, and compare the estimate with your state's official rules before making legal or financial decisions.

Short answer: Child support is calculated using your state's guideline formula, which starts with the parents' incomes and the number of children. Most states (41 plus DC) use the income shares model, 6 use a percentage of the paying parent's income, and 3 (Delaware, Hawaii, Montana) use the Melson formula.

Income shares

The state estimates what intact families at the parents' combined income spend on children, then splits that amount by each parent's share of income. The paying parent's share becomes the support amount, adjusted for parenting time, health insurance and child care.

Percentage of income

Alaska, Mississippi, Nevada, North Dakota, Texas and Wisconsin apply a set percentage to the paying parent's income. Texas, for example, starts at 20% of net resources for one child.

Melson formula

The Melson formula first sets aside a self-support reserve for each parent, then calculates the children's primary needs, and adds a standard-of-living share of remaining income.

What changes the number

Overnights with each parent, health insurance premiums, work-related child care, other children you support, and income caps can all move the final figure. Judges can also deviate from the guideline when it would be unjust.

Run the numbers with the Child Support Calculator, or talk to a lawyer about your case.

This page is general information, not legal advice. Rules differ by state and change over time.