Child Support Calculator
Estimate a monthly child support payment using an income shares model approximation.
⚠️ This is a rough educational estimate only, not legal advice. Actual child support amounts vary significantly by state guideline, court, and case specifics — consult a licensed family law attorney or your state's official child support guidelines.
How the income shares model works
Most US states base their child support guidelines on some version of the "Income Shares Model," which starts from the idea that a child should receive the same proportion of parental income they would have received if the parents lived together. It combines both parents' incomes, applies a percentage based on the number of children to determine a total support obligation, and then splits that obligation between parents in proportion to their share of the combined income. This calculator uses approximate national percentages — roughly 18% of combined income for one child, 26% for two, 30% for three, 33% for four, and 36% for five or more — scaled to your inputs.
Why this is a national approximation, not your state's guideline
Every state publishes its own official child support schedule, and the exact percentages, income caps, and adjustments differ meaningfully from state to state — some also factor in health insurance premiums, childcare costs, or extraordinary medical expenses that this simplified tool does not include. This calculator is designed to give you a reasonable ballpark using the same general model most states rely on, not a substitute for your state's specific worksheet.
How parenting time and other factors change the number
Many states reduce the paying parent's obligation as their share of overnights increases above a baseline (often around 20%), since they're directly covering more day-to-day costs during that time. Other real-world factors — childcare costs, health insurance, extraordinary medical or educational expenses, and each state's specific income caps — can shift the final number in either direction. This is a rough educational estimate only, not legal advice; actual child support orders vary significantly by state, court, and case specifics, so consult a licensed family law attorney or your state's child support agency for an accurate figure.
Frequently Asked Questions
Is this the exact amount a court will order me to pay?
No. This is a rough educational estimate using a national approximation of the income shares model. It is not legal advice and is not the same as your state's official child support worksheet. Courts apply your specific state's guidelines, which include factors this calculator does not, so consult a family law attorney or your state's child support agency for an accurate number.
What is the income shares model?
It's the model most US states use as the basis for their child support guidelines. It combines both parents' incomes, calculates a total support obligation based on the number of children, and divides that obligation between parents based on their proportional share of the combined income.
Does this calculator work for my specific state?
It uses a national approximation of the percentages many states reference, not your state's exact schedule. States vary on income caps, additional expense adjustments, and exact percentage tables, so treat this as a starting ballpark rather than your official state guideline amount.
How does parenting time affect child support?
In many states, the paying parent's obligation decreases as their percentage of overnights increases above a baseline (often around 20%), since more time with the child means covering more day-to-day costs directly. This calculator applies a simplified reduction for parenting time above 20%.
Does this include childcare or health insurance costs?
No, this simplified calculator only estimates the base obligation from income and number of children. Many real child support orders add separate line items for childcare, health insurance premiums, and extraordinary medical or educational expenses on top of the base amount.
Is child support based on gross or net income?
Most states use gross income (before taxes) as the starting point for their guidelines, though some make specific deductions for taxes, existing support orders, or mandatory retirement contributions. This calculator treats your input as gross monthly income.
Can child support amounts change over time?
Yes. Most states allow modification when there's a significant change in either parent's income, the child's needs, or the parenting time arrangement. Either parent can typically petition the court for a review.
Until what age is child support typically paid?
Most states require support until the child turns 18, though many extend it if the child is still in high school, and some states have different rules for children with disabilities or those attending college. Check your state's specific statute for the exact rule that applies to you.