Child support · guide
How much is child support?
A number for your situation, the range across states, and the handful of inputs that move it most.
Checked by Radif Partners · Editorial policy · How we calculate
For one child, a parent who earns $5,000 a month while the other parent earns $3,000 pays a median of about $763 a month across the 49 state guidelines on this site, roughly 15% of that parent's income; for two children the median rises to about $1,130. Those medians hide a wide spread, because each state counts income differently (gross, net or adjusted), uses its own table or percentage, and treats parenting time its own way. The amount you will actually see in an order depends on five inputs above all: the definition of income your state uses, both parents' incomes, the number of children, the overnights the children spend with the paying parent, and the child care and health insurance costs added to the basic amount. The mini calculator below compares states for the same family; the full calculator takes your own figures.
Same family, different state: payer $5,000, other parent $3,000 a month
Guideline support in Alabama
$647 a month
| A year | $7,764 |
| Lowest of the states shown | $566 |
| Highest of the states shown | $1,250 |
| Rank, lowest first | 8 of 49 |
Each state counts income its own way (gross, net or adjusted): the same dollar figure is not always the same income.
The five inputs that move the amount
The definition of income. It sounds technical, and it is the source of most surprises. A guideline built on gross income applies its table to pay before taxes; one built on net income starts after taxes and mandatory deductions. A parent who reads a net-income table with a gross figure will overestimate what he or she owes, and the reverse is just as common. Each state page on this site says which definition applies and what can be deducted.
Both incomes, not one. In income-shares states, the other parent's income lowers the paying parent's share. Suppose the receiving parent's income doubles: the table amount for the combined income goes up a little, but the paying parent's share of it falls, so the payment usually drops. In percentage states that look only at the payer's income, it does not move at all.
The number of children. Support rises with each child, but not in proportion: the second child adds less than the first because housing and many household costs are shared. Across the guidelines on this site, the median for two children is about $1,130 against $763 for one, for the same incomes.
Overnights. Once the paying parent has the children often enough, most states switch to a shared-parenting computation that can cut the payment sharply. The threshold is a number of overnights a year written in each guideline, so a schedule of alternate weekends plus one weeknight can land on either side of it depending on the state.
Add-ons. Work-related child care and the children's health insurance premium are usually added to the basic amount and shared by income. For a family with young children in paid care, the add-on can be larger than the basic support itself.
Low and high incomes
Guidelines protect parents with very low incomes. Some tables include a shaded low-income area, some apply a self-support reserve so that the paying parent keeps a minimum to live on, and many set a minimum order, often around fifty dollars a month, rather than nothing. At the top, most tables stop at a combined income ceiling. Above it, the state either extends the table by a percentage, freezes the amount at the top row, or leaves the figure to the judge, who looks at the children's actual needs and the standard of living. The calculator tells you when your incomes fall outside the table.
How long child support lasts
Support usually continues until the child turns 18, and in many states longer if the child is still in high school, often until 19. A few states set a different age, and some allow support for college expenses or for an adult child with a disability. The state pages quote the exact rule. Ending support is not automatic everywhere: in several states the paying parent must ask the agency or the court to close the case when the last child emancipates.
Changing the amount later
An order can be modified when circumstances change substantially, such as a job loss, a large raise, a change in custody or new medical needs. Many states define “substantial” with a threshold, for example a recalculated amount that differs by a set percentage from the current order, and many child support agencies review orders every few years on request. Until a court changes the order, the old amount stays due, and arrears generally cannot be forgiven retroactively.
A worked example
Consider a mother with primary custody of two children who earns three thousand dollars a month and a father who earns five thousand. In an income-shares state, their combined eight thousand dollars is located in the state table for two children, and the father owes five eighths of the table amount, plus five eighths of the child care and the children's health premium. If the father has the children every other weekend and one weeknight, about a hundred nights a year, he may or may not reach his state's shared-parenting threshold, and that single fact can change the order by several hundred dollars a month. In a percentage state such as Texas, the mother's income does not enter the basic calculation at all. Use the mini calculator above to compare states with these incomes.
Who collects and enforces support
Every state runs a child support agency under Title IV-D of the Social Security Act. It can locate a parent, establish paternity, set and modify orders, and collect through income withholding, tax refund interception and license suspension. Its services are open to any parent, usually for a small application fee, and they are automatic for families receiving public assistance. Payments often flow through the state disbursement unit, which keeps a record that settles later disputes.
To check your own case, open the child support calculator, choose your state and enter both incomes as your state defines them, the number of children and the overnights. The steps under the result show the table amount or the formula, each parent's share and the adjustments applied.