Child support for one child has no fixed national amount

There is no single dollar figure that applies everywhere. Every state sets its own formula, and the amount depends on both parents' income, custody arrangement, and other factors specific to your case. A parent in California paying support for one child might owe $400 a month; the same income in Texas might result in $600. The only way to know what you or the other parent would owe is to run the numbers through your state's formula or ask a family law attorney who knows your state's rules.

Child support is calculated, not guessed. The court or the child support agency uses a worksheet that plugs in income figures and applies a percentage or formula set by state law. That worksheet is public — you can find it on your state's child support enforcement website — but the math only works if you have accurate income information for both parents.

Key Takeaways

  • Child support amounts are determined by state law formulas that vary widely; there is no national standard amount for one child.
  • The calculation depends primarily on both parents' gross income, custody time-sharing, and whether either parent pays for health insurance or childcare.
  • Most states publish their child support worksheets online, and you can estimate your state's amount by entering income figures into that worksheet.
  • The amount set by a court order can be modified if either parent's income changes significantly or custody arrangements change.

How states calculate the amount

Most states use one of two methods: the income shares model or the percentage of income model. Under income shares, the court adds both parents' incomes, looks up what percentage of that combined income should go to the child, then divides that obligation between the parents based on each one's share of the total income. Under percentage of income, the obligor (the parent paying) simply pays a set percentage of their gross income — often 17 percent for one child, though this varies by state.

The calculation starts with gross income, not take-home pay. Gross income usually includes wages, salary, bonuses, self-employment income, rental income, and sometimes Social Security or disability payments. It does not typically include means-tested benefits like TANF or SNAP. If a parent is self-employed or has irregular income, the court may average income over a period of time or use tax returns to establish a baseline.

After the base amount is calculated, the court may adjust it up or down based on other factors: whether one parent pays for health insurance for the child, whether one parent pays for childcare so the other can work, how much time each parent spends with the child, and whether either parent has other children from other relationships. These adjustments can raise or lower the final amount significantly.

Income ranges by state and custody split

Because formulas differ, the same income produces different amounts in different states. A parent earning $50,000 a year with one child and 20 percent custody might owe roughly $400 to $700 per month depending on the state. A parent earning $100,000 might owe $800 to $1,400. These are rough ranges; your actual amount depends on your state's specific formula, the other parent's income, and adjustments the court makes.

Custody time-sharing also shifts the amount. If one parent has the child 80 percent of the time and the other 20 percent, the parent with 20 percent custody usually pays more than if they had 50-50 custody. Some states reduce the obligation significantly when custody is split evenly, because both parents are already spending money on the child during their time. A few states have formulas that account for overnight stays rather than just legal custody.

If you want a rough estimate, find your state's child support worksheet online — most state child support enforcement offices publish them — and enter your income and the other parent's income. The worksheet will show you the calculation step by step. This is not a legal information, but it will give you a realistic picture of what the formula produces.

What income counts and what does not

Courts count gross income from most sources: W-2 wages, 1099 self-employment income, rental income, interest and dividends, Social Security benefits (in most states), workers' compensation, unemployment insurance, and bonuses or commissions. Some states also count alimony or spousal support received from another relationship.

Courts typically do not count means-tested public benefits like TANF, SNAP, SSI, or Medicaid. They also usually do not count child support received from another child's other parent. Some states exclude certain tax credits like the Earned Income Tax Credit from the income calculation, though this varies. If a parent is voluntarily unemployed or underemployed — meaning they could earn more but choose not to — the court may impute income, or assign an income level based on their education, work history, and local job market, rather than accepting their actual low earnings.

When the amount changes

A child support order is not permanent unless the court says it is. Either parent can request a modification if circumstances change significantly. Most states allow modification if there has been a substantial change in circumstances — usually defined as a 10 to 15 percent change in either parent's income, a change in custody, or a change in the child's needs.

If the paying parent loses a job, their income drops, or they take a lower-paying position, they can file to reduce the amount. If the receiving parent's income increases significantly or the paying parent's income rises, the other parent can file to adjust it. A change in custody — for example, the child moving to live primarily with the other parent — also triggers a modification. The process requires filing paperwork with the court or child support agency and usually involves a hearing or agreement between both parents.

Modifications are not automatic. The parent seeking the change must file the paperwork and prove the change in circumstances. Until a new order is issued, the old amount remains in effect. If you stop paying because you believe the amount is unfair, you can accumulate arrears (back payments) that the court can enforce through wage garnishment, tax refund interception, or other collection methods.

How to find your state's formula

Start with your state's child support enforcement office website. Every state has one, usually run by the Department of Human Services, Department of Social Services, or Attorney General's office. Search "[your state] child support enforcement" or "[your state] child support guidelines." The site will have the current formula, the worksheet, and often a calculator tool.

If you need the exact amount for your situation, you have two options: use the online calculator if your state provides one, or consult a family law attorney in your state. An attorney can review your specific income, custody arrangement, and any special circumstances and tell you what the court would likely order. Some legal aid organizations offer free or low-cost consultations for child support questions.

If a child support order already exists and you believe the amount is wrong — either because income has changed or because the original calculation was incorrect — you can file a motion to modify with the court or contact your state's child support enforcement office to request a review.

Frequently Asked Questions

Does child support change if I get custody of the child?

Yes. If custody changes, the child support obligation usually changes too. If you go from paying support to having primary custody, the other parent would typically owe you support instead. You must file a modification request with the court to change the order; the old amount does not stop automatically.

What if the other parent makes much more money than me?

Most states have income caps or use different formulas for very high incomes. Once income exceeds a certain threshold — often $150,000 to $250,000 depending on the state — the court has discretion in how much additional support to order. The court considers the child's actual needs and the parents' standard of living, not just a percentage calculation.

Can child support be waived if both parents agree?

Not entirely. Parents can agree to an amount different from what the formula produces, but the court must approve it and it must be in the child's best interest. A court will not approve an agreement where one parent pays nothing if the formula would require payment, because child support is considered the child's right, not a matter for parents to bargain away.

Does child support include healthcare and childcare costs?

The base child support amount is for living expenses. Healthcare and childcare are usually added on top. The court typically orders the parent with better insurance to cover the child, and both parents may share childcare costs based on their income. These are separate line items on the worksheet, not included in the base amount.

What happens if I cannot afford the amount ordered?

If your income drops or circumstances change, you can file to modify the order. You must file before you fall behind; if you simply stop paying, arrears accumulate and the court can enforce collection. If you file for modification and the court agrees your circumstances have changed, the new amount applies going forward, though you may still owe some or all of the arrears from the period before modification.