Child Support Calculator & Worksheet
Interactive guidelines worksheet & AI-driven deviation analysis.
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Frequently Asked Questions
What is the Income Shares Model?
The Income Shares Model is based on the concept that the child should receive the same proportion of parental income that they would have received if the parents lived together. Most US states use this model for calculations.
What counts as gross income for child support?
Gross income usually includes salary, wages, bonuses, commissions, self-employment earnings, alimony received, pension payments, and social security benefits. Deductions vary by state but typically include income taxes, mandatory retirement contributions, and other child support orders.
How does parenting time affect the calculation?
In states using joint custody rules, a parent's child support obligation is adjusted downward if the child spends more than a threshold number of nights with them (commonly 73 to 110 nights depending on the state). The more time the child spends with you, the lower your cash support obligation generally is, because you are directly paying for food and lodging during your custody time.
How Child Support is Calculated: A Guide to the Models
Child support calculations in the United States generally follow one of three primary guidelines models: the Income Shares Model, the Percentage of Income Model, or the Melson Formula. The most common is the **Income Shares Model**, used by over 40 states. This model aggregates the income of both parents, determines a basic support obligation from a state-mandated table (representing what intact families with that income typically spend on children), and then divides that obligation proportionally between the parents based on their respective contributions to the total income.
The **Percentage of Income Model** is simpler and is used by states like Texas. Under this model, child support is calculated solely as a flat percentage of the non-custodial parent's net income, regardless of what the custodial parent earns (e.g., 20% for one child, 25% for two children in Texas). The **Melson Formula** (used in Delaware, Hawaii, and Montana) is a more complex version of the Income Shares model that incorporates a self-support reserve for each parent before determining child support obligations.
Understanding Deviations and Adjustments
State formulas calculate a presumptive child support amount. However, judges have the discretion to deviate from this guideline amount if they find that the standard calculation is unjust or inappropriate for a specific family. Common deviation factors include extraordinary medical expenses for a child, special educational needs, high travel costs incurred during visitation, extreme income disparities, or when a parent supports children from other relationships.
Furthermore, adjustments are almost always made for direct expenses paid by one parent, such as health insurance premiums and work-related child care costs. These expenses are added to the basic obligation and shared proportionally, with the parent who pays them directly receiving a credit against their cash support obligation.
Filing and Enforcing Child Support Orders
To establish a formal child support order, a parent must file a petition with their local family court or apply for services through their state's child support enforcement agency (often part of the Department of Social Services or Attorney General's office). Once ordered, child support is typically collected via income withholding (wage garnishment) directly from the paying parent's paycheck. If circumstances change significantly—such as a job loss or a shift in the physical custody schedule—either parent can request a formal modification of the child support order.