FullCalculator

Child Support Calculator

Income Shares Model

Estimate child support using the income shares model (used by most US states)

$
$
%
$
$

Formula

Child Support = (Combined Income × Child Rate) × Non-Custodial Parent's Income Share, adjusted for custody percentage. Typical rates: 1 child = 17%, 2 = 25%, 3 = 29%, 4 = 31%, 5 = 35%.

Frequently Asked Questions

How is child support calculated?
Most US states use the 'income shares' model, which considers both parents' incomes, number of children, custody arrangement, and additional expenses like healthcare and childcare. The goal is to give children the same proportion of parental income they would have received if the parents lived together.
Can child support be modified?
Yes. Either parent can request a modification if there is a significant change in circumstances, such as a major income change, change in custody, or change in the child's needs. Most states allow modifications every 2-3 years or when income changes by 15-20%.
Until what age is child support paid?
In most states, child support continues until the child turns 18 or graduates high school (whichever is later). Some states extend support to age 19 or 21, especially if the child is in college.

You may also need