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Child support calculator: the guideline amount, and what your state's formula actually does
Every state has a formula, but they differ in kind. Percentage-of-income states (Texas, Wisconsin, Mississippi, Alaska, Nevada) take a fixed share of one parent's income — and where the formula uses income after tax, the taxes are computed here from the 2026 tables, exactly as the guidelines direct. Income-shares states combine both parents' incomes against a schedule; for those the page explains the method and gives the after-tax figure their worksheets begin with. Free; not legal advice.
Three models
- Percentage of income (TX, WI, MS, AK, NV, and a few others): a percentage of the paying parent's income by number of children, sometimes capped (Texas: $11,700 of net resources a month).
- Income shares (about 40 states): the combined parental income sets a basic support amount from a schedule, split pro rata, then adjusted for parenting time, health insurance and child care.
- Melson formula (DE, HI, MT): income shares with a self-support reserve first.
Courts start from the guideline and may deviate for special needs, high income, shared custody or agreements between the parents. Use the state's official calculator or worksheet for anything you file.
Frequently asked
Why single-filer tax rates?
Most guidelines compute net income for a single person claiming only themselves, regardless of actual filing status, so the result does not depend on who claims the children.
Does the receiving parent's income matter?
Not in percentage states like Texas; yes in income-shares states, which is why they need both incomes.
How is 50/50 custody handled?
Each state has its own adjustment (offsets, credits, or a separate formula); the guideline number here assumes the standard arrangement.