Select Your State
Each calculator uses the state's official guideline formula updated for 2025.
What Is Child Support?
Child support is a court-ordered payment from one parent (usually the non-custodial parent) to the other to help cover the costs of raising a child. Payments are meant to ensure that children benefit from the financial resources of both parents, regardless of which parent they primarily live with.
Every state is required to maintain numerical child support guidelines, and courts are generally expected to follow them. As a result, the vast majority of child support orders in the United States are set using a formula — which is exactly what our calculators estimate.
The Three Models States Use
Percentage of Income
Only the paying parent's income determines the amount. Texas and Wisconsin use this model. Simple to calculate but criticized for not accounting for the receiving parent's income.
Texas · Wisconsin · Alaska
Income Shares
Both parents' incomes are combined to determine what the child would have received if the household were intact. Each parent pays a pro-rated share. Used by most states.
California · Florida · Georgia · Illinois · Ohio + more
Melson Formula
A modified Income Shares approach that first ensures each parent meets their own basic needs, then allocates remaining income to child support. Used by Delaware, Hawaii, Montana, and Pennsylvania.
Pennsylvania · Delaware · Montana
Frequently Asked Questions
States use one of three models: Percentage of Income (the paying parent's income only), Income Shares (both parents' incomes combined), or the Melson Formula (a variation of Income Shares with a self-support reserve). Each state sets its own guideline percentages, schedule tables, and allowable deductions. Courts generally follow the state guidelines but can deviate based on individual circumstances.
These tools provide reasonable estimates based on each state's published guideline formula. Real court orders involve additional factors — exact tax calculations, judicial discretion, health insurance credits, childcare costs, and possible deviations — that can shift the final number significantly. Use these estimates as a starting point for understanding the range, not as a prediction of what a court will order.
No — these are free, self-service tools for educational purposes. However, if you are involved in a child support case, consulting a licensed family law attorney in your state is strongly recommended. An attorney can account for all relevant facts, represent your interests in court, and advise on modification of existing orders.
Gross income is your total earnings before any deductions. Net income (or net resources) is what remains after mandatory deductions such as federal and state income taxes, Social Security, and Medicare. Some states base child support on gross income (e.g., Georgia, Ohio), while others use net income (e.g., Texas, Illinois, California). Each calculator specifies which income type it uses.
Yes. Most states allow modification when there has been a "substantial change in circumstances" — typically a significant change in either parent's income, a change in custody, or a change in the child's needs. The threshold and process vary by state. You generally must file a petition with the court that issued the original order. Calculators can help you estimate what a modified order might look like.