Get a rough idea of monthly child support based on income and number of children. This free child support calculator is an educational estimate only — actual amounts are set by your state or country’s official guidelines and a court.
⚠ Rough educational estimate only — not legal advice. Actual child support is set by your state or country’s official guidelines and a court.
Estimate inputs
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This model applies a flat percentage of the paying parent’s net income. Many states use more detailed “income shares” formulas that also factor in both parents’ incomes, custody time, health care and childcare.
Estimated monthly support
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Enter income and number of children
Guideline percentage
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Children
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Annual estimate
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Net income used
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For an accurate figure, use your state or country’s official child support calculator and consult a family law attorney.
This free child support calculator gives a rough, educational estimate of monthly child support based on the paying parent’s income and the number of children. It is not a legal determination — real orders are set by your state or country’s official guidelines and a court.
What this child support calculator does
Read this first: a child support calculator like this one can only give a ballpark figure. It applies a simple percentage of the paying parent’s net income. Actual child support is decided by law in your jurisdiction and varies widely between US states and between countries. Use this only to get a rough sense of scale, then rely on your official calculator and a family law attorney.
How child support is actually calculated
Most US states use one of two main models, and the result can differ substantially from a flat percentage:
Model
How it works
Income shares
Used by most states. Combines both parents’ incomes, estimates the cost of raising the child, and splits it in proportion to each parent’s income.
Percentage of income
Applies a percentage to the paying parent’s income only (the simplified model this tool uses).
Melson formula
A more complex model used by a few states that also reserves a basic needs amount for each parent.
Real orders also adjust for parenting/custody time, health insurance, childcare, other children, and special expenses — none of which a simple estimate captures.
How to use this estimate
Enter the paying parent’s net monthly income. Income after taxes.
Select the number of children. The percentage rises with more children.
Treat the result as a starting point only — not the amount a court will order.
Where to get an accurate figure
Your state or country’s official child support calculator — most US states publish one on their child support or judiciary website, and it reflects the exact local formula.
A family law attorney — for advice specific to your situation, custody arrangement and finances.
Your local child support agency — which administers and enforces orders.
Child support terms glossary
Term
What it means
Child support
Payments to help cover a child’s living costs after parents separate.
Paying (non-custodial) parent
The parent who typically makes support payments.
Income shares model
The most common method, based on both parents’ combined income.
Net income
Income after taxes and certain deductions.
Parenting time
Custody share, which often adjusts the support amount.
Child Support Calculator FAQ
How accurate is this child support calculator?
It's a rough estimate only. It applies a simple percentage of the paying parent's net income and does not reflect any specific state or country's official formula. Real orders are set by law and by a court, so use this only for a ballpark figure.
How is child support actually calculated?
Most US states use an "income shares" model that combines both parents' incomes and splits the estimated cost of raising the child. Others use a percentage-of-income or Melson formula. Orders also adjust for custody time, health care and childcare.
What income is used for child support?
Guidelines typically use net (after-tax) income, though the exact definition — and what deductions count — varies by jurisdiction. This tool uses the paying parent's net monthly income.
Does custody or parenting time affect child support?
Yes. In most jurisdictions the amount of time a child spends with each parent affects the support amount, often reducing it as shared parenting time increases. A simple estimate can't capture this.
Where can I get an official child support figure?
Use your state or country's official child support calculator, usually on the child support agency or judiciary website, and consult a family law attorney for advice specific to your situation.
Is the child support calculator free to use?
Yes, this child support calculator is completely free, needs no sign-up, and gives an instant estimate directly in your browser.
