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Child Support Calculator

Estimate child support payments based on income, custody arrangement, number of children, and state guidelines.

Tested tool guide Tested browser tools Checked August 16, 2026

What Child Support Calculator does and how it behaves

Child support is a state law, not a federal one, so the same family pays different amounts in different states. This tool walks through the inputs the states actually use: each parent's gross income, the number of children, how parenting time is split, and which state's guidelines apply, then returns a monthly estimate. The thing most people get wrong: most states base the payment on both parents' combined income, not just the higher earner's, and a 50/50 custody split does not automatically mean no payment when the incomes differ.

How the result is produced

1

Inputs it gathers

You supply each parent's gross monthly income, the number of children covered, the custody arrangement expressed as parenting time, and the state whose guidelines apply. From that the tool produces a monthly figure using that state's schedule. Most states use an income-shares model, combining both parents' incomes and splitting the guideline amount proportionally; a minority apply a straight percentage of the paying parent's income.

2

What the output is

The result is the guideline amount, not a court order. It is the presumptive starting figure in most states, but judges may deviate for reasons such as extraordinary expenses, high combined income, or unusual parenting schedules. Health insurance premiums and child care are often handled as add-ons on top of the base amount, so the displayed figure rarely covers every cost in a real order.

Good uses

  • Negotiating a private support agreement and wanting a defensible starting number before spending money on a lawyer.
  • Testing how a custody change, a raise, or a new job would move the payment before any filing.
  • Budgeting for what support might cost or bring in after a separation, as part of divorce or custody planning.

Limits and checks

  • The state selection drives everything. The same income and custody inputs produce different results under different state schedules, so an estimate built on the wrong state is misleading rather than merely approximate.
  • Income definitions differ. Some states count bonuses and gifts, others impute income to an unemployed or underemployed parent, and most use gross rather than take-home pay. Entering take-home pay where a state expects gross, or vice versa, shifts the result.
  • The figure is an estimate, not a prediction. Add-ons such as insurance and child care, plus judicial deviation, can change a final order, and state guidelines are revised over time. Treat the number as a planning range rather than a quoted amount.

Common questions

Is this number what I will actually pay or receive?

Probably close, but not guaranteed. The figure reflects guideline formulas, which most states treat as a presumptive amount a judge may depart from for reasons the calculator cannot see, such as medical costs, travel, or high income. It is a planning estimate you can take to a lawyer, not a figure a court is bound to order.

Does a 50/50 custody split mean no child support?

Not automatically. When parenting time is shared but incomes differ, most states still order a payment, often by combining both incomes and splitting the guideline amount proportionally; some shared-parenting formulas reduce the amount for substantial parenting time but do not zero it out. The result depends on the state and on how the tool counts the custody split.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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