US Child Support Calculator

Estimate guideline child support in Texas, Florida, California, Illinois or Indiana from both parents' income, overnights, health insurance and childcare.

Reviewed by Dany, RightSums team · Updated

Runs in your browser. Free, no sign-up.

personal-finance · Daily life · US

Pick your state and enter each parent's gross monthly income, the number of children, overnights with the paying parent, and any health insurance or childcare costs. The calculator applies that state's own guideline: Texas takes a percentage of the paying parent's net resources (20% for one child, up to the $11,700 cap); Florida, Illinois and Indiana combine both incomes and use their income shares schedules; California runs the Family Code section 4055 formula with its K factor and time-share. You get the monthly and annual figure, every step of the working, the notes a court would consider, and a link to the state's official calculator or worksheet. Net income is estimated from gross pay, so treat the result as a guideline starting point, not the order.

Accepted inputs

  • State
  • Each parent's gross monthly income
  • Number of children
  • Overnights a year with the paying parent
  • Children's health insurance premium and who pays it
  • Work-related childcare and who pays it
  • Other children or support orders of the paying parent

Outputs

  • Guideline child support a month, a year and a week
  • Step-by-step working using the state formula
  • Notes on caps, low-income rules, time-sharing and deviations
  • What would change the amount
  • Link to the official state calculator or worksheet

How to use the US Child Support Calculator

  1. Choose your state, then enter the paying parent's gross monthly income and, except in Texas, the receiving parent's income too.
  2. Add the number of children, the overnights a year the children spend with the paying parent, and any health insurance or work-related childcare costs with who pays them.
  3. The tool estimates each parent's net income (federal tax as a single filer, Social Security and Medicare, and state tax where the state charges it), then applies the state's guideline: the Texas percentage table and cap, the Florida income shares schedule and time-sharing formula, the California section 4055 formula, or the Illinois and Indiana income shares schedules.
  4. You see the monthly and annual amount, each step of the working, the notes that matter in your state and a link to the official calculator or worksheet so you can check the figure with your real tax position.

Frequently asked questions

How much is child support in Texas for one child?

20% of the paying parent's monthly net resources, capped at $11,700 of net resources from 1 September 2025. On $4,000 gross a month, net resources are about $3,395.67 after Social Security, Medicare and federal tax, so guideline support is $679.13 a month. Two children take 25%, three 30%, four 35% and five or more 40%. Lower percentages apply under $1,000 net.

What is the maximum child support in Texas?

The guideline percentages apply only to the first $11,700 of monthly net resources (the cap set by the Attorney General from 1 September 2025). That makes the standard maximum $2,340 a month for one child, $2,925 for two and $3,510 for three. A court can order more above the cap only if the child's proven needs justify it.

How is child support calculated in Florida?

Florida combines both parents' net incomes and reads the basic obligation from the schedule in section 61.30, then splits it by each parent's share of income. With one parent on $3,000 gross and the other on $2,000, combined net is about $4,373, the schedule gives $889 for one child, and the higher earner's 59.3% share is $526.93 a month before any health insurance or childcare is added.

Does 50/50 custody change child support in Florida?

Yes. Once the paying parent has at least 73 overnights a year (20%), Florida multiplies the basic obligation by 1.5, works out each parent's share, multiplies it by the other parent's percentage of overnights and pays the difference. In the $3,000 and $2,000 example, 146 overnights cut the transfer from $526.93 to $256.99 a month. Courts can also vary the result by 5% either way.

How does the California child support formula work?

California uses CS = K × [HN minus H% × TN]: the higher earner's net disposable income, their share of time with the children and both parents' combined net income, with K set by income and time-share. A parent on $6,000 gross with 73 overnights, the other on $3,000, pays about $985.53 a month for one child; two children multiply that by 1.6 to $1,576.85.

Sources

The rates and rules in this tool come from:

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