How Child Support Is Calculated in Your State (and Why Online Calculators Matter in 2025)

By State Child Support Calculator •

Conceptual illustration of child support, showing a silhouette of a father and child next to a large calculator and scales of justice balancing a child's needs against financial cost.

Navigating child support can be confusing because every state sets its own rules, percentages, and income limits. Whether you are budgeting for the months ahead or just want to understand how support is determined, this guide explains the basics and gives you an easy way to estimate payments for your state.

Quick start: Choose your state to get a guideline estimate right now.

California

Income Shares (state variant)

Texas

Percentage of Income

New York

Income Shares

Florida

Income Shares

Pennsylvania

Income Shares

Illinois

Income Shares

Prefer a different state? See the full map.

How Child Support Works Across States

Each state uses its own formula to determine child support, based on parents’ income, custody schedules, and the number of children. While details differ, most states follow one of three core models:

Income Shares Model

Both parents’ incomes are combined to estimate what they would spend on their children if living together. The cost is split proportionally.

Percentage of Income Model

A fixed percentage of the obligor’s income, adjusted by number of children. Some states also apply income caps.

Melson Formula

A variation that includes a self-support reserve and standard-of-living adjustments. Used by a few jurisdictions.

Why We Built This Tool

  • 50 states + D.C. Coverage designed to reflect each state’s current guideline framework.
  • Updated for 2025. Our goal is to keep caps, tables, and factors aligned with official guidance.
  • Plain-English explanations. You do not need a law degree to understand your estimate.
  • Privacy-friendly. No account required to run a calculation.

What to Expect From Your Estimate

The calculator is a starting point. Courts may adjust amounts for factors such as:

  • Health insurance premiums and out-of-pocket medical expenses
  • Work-related child care or education costs
  • Parenting time or shared custody arrangements
  • Extraordinary expenses, travel, or special needs

Tip: Run a few scenarios to see how changes in income, custody time, or expenses affect your result. Bring those scenarios to discussions with your co-parent or attorney.

Try It Now

Get a quick estimate for your situation in under a minute.

Open the Calculator

Frequently Asked Questions

Is the calculator result the same as a court order?

No. It is a guideline estimate. Judges can deviate based on evidence, local rules, and the child’s best interests.

Do I need both parents’ incomes?

Income Shares and Melson usually require both. Percentage of Income typically uses only the obligor’s income.

Can I include health insurance or child care?

Many states add or credit these costs. Enter them where prompted, or model them as adjustments if your state handles them outside the base formula.

Disclaimer: This article and calculator are for informational purposes only and not a substitute for legal advice. For advice about your specific case, consult a licensed family law attorney in your state.

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