Child Support Calculator
Estimate monthly child support based on your state's guidelines, income, and custody arrangement.
Family Information
Estimated Monthly Child Support
$1,153/mo
Paid by: Parent A (California)
Calculation Details
Important
This is a rough estimate for informational purposes only. Actual child support is determined by a court based on state-specific guidelines, your complete financial picture, and the best interest of the child.
How Child Support Is Calculated
Every state has guidelines for calculating child support, but they use different models. The two main approaches are the Income Shares Model (used by most states) and the Percentage of Income Model. Both consider parental income, number of children, custody time, and additional expenses like health insurance and child care.
Child Support Models by State
| Model | How It Works | States |
|---|---|---|
| Income Shares | Both parents' income determines total obligation, split by ratio | Most states (39+) |
| Percentage of Income | Fixed % of non-custodial parent's income | TX, WI, ND, MS |
| Melson Formula | Income shares variant with self-support reserve | DE, MT, HI |
Factors That Affect Child Support
Beyond income, courts consider the number of overnights each parent has (shared custody often reduces payments), health insurance costs, child care expenses, special needs, and existing support obligations for other children. Judges have discretion to deviate from guidelines based on the child's best interests.
OCSE — Child Support Information for Parents→Frequently Asked Questions
How long does child support last?
In most states, child support continues until the child turns 18 (or 19 if still in high school). Some states extend it through college (until 21-23). Support may also end if the child is emancipated, gets married, or joins the military.
Can child support be modified?
Yes — either parent can request a modification when there's a "substantial change in circumstances" such as job loss, significant income change, or change in custody arrangement. Most states allow modifications every 2-3 years or with a 15-20% income change.
Is child support tax-deductible?
No. Child support is not deductible for the payer and not taxable income for the recipient. This differs from alimony, which had different tax treatment prior to 2019.
Related: Alimony Calculator and Child Care Cost Calculator.