👨‍👧 Child Support Calculator — Estimate Your Monthly Payment by State

Estimate monthly child support using the income shares model — the formula used by most US states.

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Child Support Estimator

Uses the income shares model. Results are estimates — courts apply state-specific guidelines. All calculations stay in your browser. · Updated 2026

Estimated Monthly Child Support Payment
Combined Parental Income
Basic Child Support Obligation
Paying Parent's Income Share
Custody Adjustment Applied

⚠️ Important: Child support formulas vary significantly by state. This calculator provides an estimate using the income shares model. Courts may deviate based on healthcare costs, childcare costs, extraordinary expenses, and other factors. Only a court order is legally binding. Consult a family law attorney for your state's specific guidelines.

Child support amounts vary significantly by state, but typically range from $400–$1,200 per month per child for middle-income families in 2026. Most states use the "income shares" model, calculating support based on both parents' combined gross income and the estimated cost of raising children at that level. Custody arrangements, childcare costs, and health insurance premiums all factor into the final order. Use this calculator to estimate your state's likely obligation — then consult a licensed family law attorney for advice specific to your situation.

How Child Support Is Calculated

In income shares states, the process is: (1) Add both parents' gross (or net, depending on state) monthly incomes; (2) Look up the basic child support obligation for that combined income and number of children in state guidelines tables; (3) Calculate each parent's percentage share of combined income; (4) The paying parent's share of the basic obligation is their base child support payment; (5) Adjustments are made for health insurance costs, childcare, extraordinary medical expenses, and custody time (with significant custody time often reducing the payment).

What Can Modify a Child Support Order?

Child support orders can be modified when there is a "substantial change in circumstances" — typically a change in income of 15–20% or more, a change in custody arrangement, a change in the child's needs, or one parent becoming unemployed or disabled. Either parent can petition the court for modification. Many states have automatic review processes every three years, particularly when the child receives public assistance. Important: private agreements between parents to informally pay less than the court order are not legally enforceable — you'll still owe the difference as arrears. Only a new court order changes the legal obligation.

What Does Child Support Actually Cover?

The base child support payment is intended to cover a child's basic needs: food, housing, clothing, and education expenses proportional to each parent's income. Most states build in additional "add-on" expenses on top of the base support: health insurance premiums, unreimbursed medical and dental costs, childcare expenses (daycare, after-school care), and sometimes extracurricular activities. These add-ons are typically split between parents in proportion to their respective incomes. It's important to understand that a child support order alone may not cover all of a child's actual expenses — high medical costs, private schooling, or significant childcare needs are often addressed separately in the court order.

Frequently Asked Questions

Most states (41+) use the "income shares" model, which calculates support based on both parents' combined gross income and the estimated cost of raising children at that income level. A smaller number of states use the "percentage of income" model, applying a flat percentage to the paying parent's income — for example, 17% for one child in Texas. Courts then adjust the base amount for custody time, work-related childcare, and health insurance costs.
The average child support payment in the U.S. is approximately $430–$500 per month for one child, according to Census Bureau surveys. However, actual amounts vary widely — families with combined incomes over $100,000/year typically see orders of $800–$1,500+/month per child. Courts generally aim to maintain the child's standard of living as close as possible to what it was before the separation.
Yes — custody time is one of the largest variables in support calculations. In most states, the more overnight parenting time the obligated parent exercises, the lower the monthly support obligation. A 50/50 custody arrangement typically reduces the base support amount by 30–50% compared to a sole-custody order, since both parents are bearing direct child-rearing costs. The exact adjustment formula varies by state.
Base child support orders generally cover housing, food, clothing, and basic education expenses. Courts separately address childcare costs (daycare, after-school care), health insurance premiums, unreimbursed medical expenses, and extracurricular activities. These "add-on" expenses are typically split proportionally between the parents based on their incomes and can increase the total monthly obligation by 20–40% above the base figure.
Most states allow modification when there is a "substantial change in circumstances" — typically defined as a 15–25% change in either parent's income, a significant change in custody, job loss, or the child's changing needs. Many states conduct automatic reviews every 3 years, and either parent can petition for modification at any time with documented evidence. Consulting a licensed family law attorney in your state is advisable before filing a modification request.

⚖️ When to Hire a Family Law Attorney for Child Support

A family law attorney is advisable when: you and the other parent disagree on income figures or custody time that affects the calculation; one parent is self-employed (making income harder to verify); either parent has complex income including bonuses, commissions, or rental income; you are seeking a modification and expect the other party to contest it; or there are arrears disputes or enforcement issues. Child support services agencies in every state (DCSS, CSE, or similar) provide free enforcement and modification services for custodial parents without requiring private counsel — a useful first resource before spending on private legal fees.