Child Support Estimator
Estimate monthly child support based on both parents' incomes, custody split percentage, number of children, and state guidelines using the income shares model.
Results
Visualization
How It Works
Child support in most U.S. states is calculated using the income shares model, which combines both parents' gross incomes, applies a percentage based on the number of children, then divides the obligation proportionally by each parent's income share. Custody time above a threshold (typically 30% overnights) triggers a downward adjustment to account for the paying parent's direct spending on the children during their parenting time.
The Formula
Variables
- Combined Income — Sum of both parents' monthly gross incomes
- Child % — Percentage of combined income allocated for children (20% for 1 child, up to 49% for 8)
- Payer Share — Paying parent's income as a proportion of combined income
- Custody Adjustment — Reduction factor when the paying parent has more than 30% custody time
- Add-Ons — Health insurance, childcare, and extraordinary expenses shared proportionally
Worked Example
Payer earns $6,000/mo, receiver earns $3,500/mo, 2 children, 20% custody: Combined = $9,500, 28% obligation = $2,660.00 + $850 add-ons = $3,510. Payer share = 63.2%. Payment = $3,510 x 0.632 = $2,218/mo ($26,618/yr).
Practical Tips
- Child support guidelines vary significantly by state -- this estimator uses a common income shares model as a starting point.
- Many states have online child support worksheets specific to their formula -- use your state's official tool for a precise estimate.
- Custody time (overnights) is a major factor in many state formulas -- a shift from 20% to 35% custody can reduce support significantly.
- Overtime, bonuses, and self-employment income are typically included in gross income calculations.
- Child support orders can be modified when there is a substantial change in income or custody arrangements.
- Child support is not tax-deductible for the payer or taxable income for the receiver (post-2018).
Frequently Asked Questions
How does custody time affect child support?
Most states reduce child support when the paying parent has the children more than a threshold amount of time, typically 25-35% of overnights. This is because the paying parent is directly spending on the children during their parenting time. The greater the custody time, the larger the reduction. Some states use a sliding scale, while others apply an abrupt adjustment at the threshold.
What counts as income for child support calculations?
Gross income for child support typically includes wages, salary, commissions, bonuses, overtime, self-employment income, rental income, dividends, interest, pensions, Social Security benefits, unemployment benefits, and workers compensation. Some states also impute income to voluntarily unemployed or underemployed parents based on their earning capacity.
How long does child support last?
In most states, child support continues until the child turns 18 or graduates from high school, whichever is later. Some states extend support to age 19 or 21, and a few allow courts to order support through college. Support may also end early if the child becomes emancipated, joins the military, or marries.
Can child support be modified after it is set?
Yes. Either parent can petition the court for a modification when there has been a substantial change in circumstances. Common grounds include a significant change in either parent's income (typically 15-20%+), a change in custody or parenting time, a change in the number of children, or a change in the children's needs such as medical expenses.