Child-support guides.
Plain-language guides to how child support is calculated in the United States: which income counts, how parenting time and added costs change the result, and how to prepare the records a court or agency will ask for. Each guide cites the federal rule or state source behind it and links to the matching state calculator.
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How child support is calculated in the United States
The three guideline models states use, a worked income-shares example, and the steps that follow the basic obligation.
Gross or net income: which number your state uses
The income definition behind each state calculator, why take-home pay is the wrong shortcut, and how to convert pay periods.
Prepare income for a child-support worksheet
Convert pay periods, avoid double counting and organize the records for your state’s income definition.
Understand your child-support estimate
Follow a worked income-shares example and check parenting time, expenses, rounding and adjustments.
Parenting time and added costs
How parenting time changes child support
Overnight thresholds and shared-custody formulas compared across states, with split custody explained.
Child care and health insurance in the support worksheet
How premiums, uninsured medical costs and work-related child care are shared between parents, with a worked example.
Support for children from other relationships
How guidelines treat prior support orders, children in the home, multiple families and stepchildren.
Income questions
Self-employment income for child support
Business receipts and expenses, common add-backs, self-employment tax, fluctuating income and gig work.
Imputed income in child support
When a court assigns income to an unemployed or underemployed parent, the federal factors, and the evidence that matters.
Changing an order and preparing a case
Modifying a child-support order
Federal review rules, the three-year review, the Texas modification test, incarceration and interstate cases.
The child-support document checklist
Income, self-employment, child-cost, parenting-time and state-form records to gather before you calculate.
Worked examples and related topics
New York child support: a worked example
Follow a $100,000 combined-income example through the Child Support Standards Act calculation.
Child support and spousal support
Separate the two obligations, see which comes first in the calculation, and find each state’s spousal-support rule.
Prepare a property and debt inventory
Record values, debts and evidence, and keep an inventory separate from a legal division of property.
Find the rules for your state
All 50 states have an individual guide covering the guideline model, the income definition, parenting-time rules, add-on costs, official forms and the governing source. 42 states also have a tested calculator on this site; the other 8 guides link directly to the official state calculator.
How these guides are written
Each guide is written from the governing statute, regulation or court rule, every state example is checked against the reviewed state guide on this site, and every update is dated. When a law changes, the affected guide and calculator are revised together. Read how calculations are tested or report a correction.
Updated October 17, 2026. Published by Kestervale LLC. Educational information, not legal advice. Report a correction.