Child Support Calculator

Child support calculations vary by state but generally fall into three models. Income-percentage states (like Texas and Wisconsin) apply a fixed percentage to the non-custodial parent's income based on the number of children. Income-shares states (the majority) combine both parents' incomes, determine a basic obligation from a schedule, then split it proportionally. A few states like California use algebraic formulas that factor in custody time. All states also consider health insurance and childcare costs.

Income percentage uses only the non-custodial parent's income and applies a fixed percentage. Income shares combines both parents' incomes to determine the total child-rearing cost, then assigns each parent their proportional share. Income shares is considered fairer because it reflects what would be spent on the children if the family were intact. About 41 states use income shares and 6 use income percentage.

Yes, significantly. When the non-custodial parent has substantial custody time (typically 35% or more of overnights), most states reduce child support. The logic is that a parent who spends more time with the children directly bears more costs. Some states, like California, build custody time directly into the formula. A 50/50 custody arrangement usually results in a lower obligation, though the higher earner typically still pays something.

Most states use gross income from all sources, including wages, salaries, commissions, bonuses, overtime, self-employment income, investment income, rental income, retirement benefits, and disability payments. Some states then deduct taxes and mandatory fees to arrive at net income. Income typically excluded includes means-tested public assistance (like TANF or SSI) and a new spouse's income.

Yes, child support orders can be modified when there is a significant change in circumstances. Common reasons include a significant increase or decrease in either parent's income (typically 15-20% or more), a change in custody or parenting time, a change in the child's needs (medical, educational), or the child reaching adulthood. Either parent can file a motion to modify, and some states allow administrative reviews every few years.

Courts can impute income to a parent who is voluntarily unemployed or underemployed. This means the court assigns an income they could reasonably earn based on their education, skills, work history, and local job opportunities. If the job loss is involuntary and the parent is actively looking for work, the court may use actual income or unemployment benefits. Quitting a job just to reduce child support is generally not an effective strategy.

In most states, child support lasts until the child turns 18 or graduates from high school, whichever is later. Some states extend it to 19 or 21. New York can order support until age 21. A few states allow support to continue through college graduation. Support can also end early if the child is emancipated (legally independent), joins the military, or marries. Disabled children may receive support indefinitely.

No. Child support is never a tax deduction for the payer and is not taxable income for the recipient. This differs from spousal support, which was deductible under agreements made before 2019 but lost that treatment under the Tax Cuts and Jobs Act. The parent who claims the child as a dependent gets the child tax credit — usually the custodial parent, unless the parents agree otherwise using IRS Form 8332.