Child Support Calculator by State
Estimate your monthly child support payment using your state's actual guideline formula. Every state sets support by a statewide equation, so each calculator below is built on that state's real statute — combining both parents' incomes where the law uses Income Shares, or applying the guideline percentage where it does not, and showing each step.
How child support is calculated in the United States
Unlike alimony, child support is set by a statewide guideline formula in every state — a judge starts from the number the formula produces and needs a documented reason to depart from it. What differs is the formula itself, and states fall into three families.
Income Shares is used by more than 40 states and the District of Columbia. It combines both parents' incomes, looks up the total support obligation for that combined income and the number of children on a state schedule, then divides it between the parents in proportion to their incomes. Florida, Georgia, Ohio, Illinois, Michigan, and Virginia use this model. California and New York apply closely related formulas of their own — California's algebraic guideline (Family Code § 4055) and New York's Child Support Standards Act.
Percentage of Income is simpler: it applies a flat guideline percentage to only the paying parent's income, regardless of what the other parent earns. Texas is the best-known example — roughly 20% of net resources for one child, 25% for two, and so on, up to a statutory income cap. Mississippi, Nevada, Wisconsin, and Alaska also use this approach.
The Melson formula, used in Delaware and Hawaii, is an Income Shares variant that first reserves each parent a self-support allowance before dividing the remaining income toward the children. Montana and North Dakota, sometimes grouped here in older sources, have both moved to Income Shares.
What you need to use a child support calculator
Have each parent's gross monthly income and the number of children ready. Depending on your state, the calculator may also factor in overnight parenting time, health-insurance premiums paid for the children, work-related childcare, and support obligations for other children. Each state page lists exactly what it asks for and cites the guideline statute behind the math.
Is the estimate the same as a court order?
No. These calculators produce the guideline estimate a court starts from, not a final order. Judges can deviate for shared custody, extraordinary expenses, or other children, so treat the result as a well-grounded estimate rather than a guarantee. For the rules in your state, see our state-by-state child support law guide.
Working through a separation? Our alimony calculator estimates spousal support, and the parenting-time calculator counts the overnights that move the support number. The divorce and child custody guides cover how those pieces fit together. The legal tools hub has the rest of our free calculators and document generators.
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Frequently Asked Questions
How is child support calculated?
Every U.S. state sets child support with a statewide guideline formula, but the formula differs by state. Most states use the Income Shares model, which combines both parents’ incomes and prorates the support obligation between them. A handful use the Percentage of Income model, which applies a flat percentage to only the paying parent’s income, and two states (Delaware and Hawaii) use the Melson formula. Pick your state above to calculate with its actual equation.
Is this child support calculator accurate?
Each state calculator applies that state’s current guideline formula and statute, so the estimate reflects the real math a court starts from. It is an estimate, not a court order. A judge can deviate from the guideline for shared custody, extraordinary medical or childcare costs, other children, and similar factors, so your final order may differ.
What information do I need to estimate child support?
At minimum you need each parent’s gross monthly income and the number of children. Depending on the state, the calculator may also ask about overnight parenting time, health-insurance premiums paid for the children, work-related childcare costs, and support paid for other children.
Does the child support calculator cost anything?
No. Every state child support calculator on this page is free, requires no sign-up, and does not store the figures you enter.
Which states use the Income Shares model?
More than 40 states and the District of Columbia use Income Shares or a close variant, including Florida, Georgia, Ohio, Illinois, Michigan, and Virginia. California and New York apply related formulas of their own — California’s algebraic guideline (Family Code § 4055) and New York’s Child Support Standards Act. Texas, Mississippi, Nevada, Wisconsin, and Alaska use the Percentage of Income model, and Delaware and Hawaii use the Melson formula.
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