Does the judge just pick a child support number?

No. Your state uses a formula, and the court applies it to real inputs like income and the number of children. That is why the result is more predictable than most people expect. The math is set by the state's rules.

Do both parents' incomes count, or only the paying parent's?

It depends on your state's approach. Some states use an income-shares model that looks at both parents' incomes together, then divides the responsibility based on what each earns. Others set support as a percentage of the paying parent's income, scaled to the number of children. Both approaches aim for steady support for the child.

Will more children mean more support?

Generally, yes. In the percentage-based approach, the percentage of the paying parent's income goes up as the number of children goes up. In the income-shares approach, the estimated amount a child would have received also rises with more children. The exact effect depends on your state's formula.

Can I figure out my own child support amount from this guide?

No. This is general information about how the approaches work, not a calculation of your specific obligation, and it is not legal advice. Your real number comes from your own honest financial information run through your state's process. If you want to understand your exact situation, your state's official self-help filing resource is a good starting point.

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How Does a Court Decide Child Support?

Legal Basics5 min readUpdated 2026-06-14

A court decides child support using a formula set by your state. A judge does not pick the number by feel. Across states, the formulas fall into two main approaches. The first, called income shares, looks at both parents' incomes together, plus things like parenting time, and estimates what the child would have received if the family stayed together. The second sets support as a percentage of the paying parent's income, scaled to how many children there are. Either way, the math is built into your state's process. You do not calculate your own obligation here. This is general information to help you feel less in the dark.

Child support comes from a state formula. Here is a plain-English look at the main approaches so the unknown number feels a little less scary.

The number comes from a formula

If you are lying awake wondering what you will owe or what you will receive, that fear is completely understandable. Here is something that helps. Child support comes from a set formula that your state has already written down. The court takes real inputs, like income and the number of children, and runs them through those rules. That means the outcome is far more predictable than it feels right now. You are working inside a system with a known shape, and you can learn how that shape works.

Approach one: both parents' incomes, looked at together

Many states use what is called an income-shares approach. The idea is fairly intuitive. The court looks at both parents' incomes, adds them together, and estimates what the child would have received if the household had stayed whole. Then it divides that responsibility between the two parents based on what each one earns. Colorado, Connecticut, and Utah work this way. California's guideline follows a similar idea, combining both parents' incomes and factoring in how parenting time is shared. So if you earn less, your share is usually smaller. The formula is trying to keep the child supported in a steady way.

Approach two: a percentage of the paying parent's income

Other states keep it simpler. Support is set as a percentage of the paying parent's income, and that percentage goes up with the number of children. Nevada bases it on the paying parent's gross income. Texas bases it on the paying parent's net resources, which is income after certain amounts are taken out. In both, more children means a higher percentage. The goal is the same as in the other approach: making sure the child is provided for in a way that is consistent from family to family.

What the formula actually looks at

You do not need to memorize any of this, but it can calm the mind to know what goes in. The big inputs are usually income and the number of children. Depending on the state, the formula may also consider how parenting time is divided, the cost of health insurance for the child, and certain childcare costs. None of this requires you to do the math yourself. The court, and the forms you fill out along the way, carry the calculation. Your job is to be honest and accurate about your own numbers.

Why honest financial information matters so much

Because the formula runs on real numbers, the most important thing you can do is share accurate financial information. Each state has its own financial form where you list income and expenses. When that information is complete and true, the formula produces a fair result for everyone, including your child. There is no advantage in guessing or rounding. Take your time, gather your documents, and let the form reflect your real life. Accuracy here protects you later.

This is general information, not your number

Nothing here is a calculation of what you specifically will pay or receive. Your situation has details that only your own forms and your state's process can account for. Think of this guide as a way to understand the shape of the decision. You now know support comes from a formula, that the formula is built around income and the number of children, and that your state has already decided how it works. This is general information, not legal advice. For guidance on your own situation, your state's official self-help filing resource is a good place to start.

Common questions

Does the judge just pick a child support number?: No. Your state uses a formula, and the court applies it to real inputs like income and the number of children. That is why the result is more predictable than most people expect. The math is set by the state's rules.
Do both parents' incomes count, or only the paying parent's?: It depends on your state's approach. Some states use an income-shares model that looks at both parents' incomes together, then divides the responsibility based on what each earns. Others set support as a percentage of the paying parent's income, scaled to the number of children. Both approaches aim for steady support for the child.
Will more children mean more support?: Generally, yes. In the percentage-based approach, the percentage of the paying parent's income goes up as the number of children goes up. In the income-shares approach, the estimated amount a child would have received also rises with more children. The exact effect depends on your state's formula.
Can I figure out my own child support amount from this guide?: No. This is general information about how the approaches work, not a calculation of your specific obligation, and it is not legal advice. Your real number comes from your own honest financial information run through your state's process. If you want to understand your exact situation, your state's official self-help filing resource is a good starting point.

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Paxora is not a law firm and does not provide legal advice. This guide is informational. For advice specific to your situation, consult a licensed family law attorney in your state.