Family Law Tools

Child Support Calculator

Estimate monthly child support payments for all 50 US states. Uses Income Shares, Percentage of Income, and Melson Formula models based on your state's guidelines.

Monthly Gross Income

👤
Paying Parent
(Non-custodial)
$
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Receiving Parent
(Custodial)
$

Additional Monthly Expenses (optional)

$
$
$
$

Child Support Calculation Models Explained

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Income Shares Model
Most states (38+)

Estimates total child-rearing cost based on combined parental income, then divides it proportionally. Both parents are seen as responsible. Most equitable method.

  1. Add both parents' monthly incomes
  2. Look up basic child support obligation from state table
  3. Divide by proportion of each parent's income
  4. Non-custodial parent pays their share
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Percentage of Income Model
TX, WI, IL, AK

Applies a fixed percentage to only the paying parent's net income. Simple and predictable. Does not consider receiving parent's income.

  1. Calculate paying parent's net monthly income
  2. Apply state percentage for number of children
  3. 1 child: 20–27%, 2 children: 25–35%, 3+ children: 29–40%
  4. Additional expenses added separately
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Melson Formula
DE, HI, MT

Most complex — first reserves income for each parent's own basic needs, then calculates support from surplus income. Considered most equitable by supporters.

  1. Determine each parent's self-support reserve
  2. Calculate children's primary support need
  3. Determine standard of living adjustment
  4. Apply formula to net income above reserves

Percentage Model States — Child Support Rates

States using percentage of paying parent's net income.

State 1 Child 2 Children 3 Children 4 Children 5+ Children
🤠 Texas 20%25%30%35%40%
🧀 Wisconsin 17%25%29%31%34%
🌿 Illinois 20%28%32%40%45%
🐻 Alaska 27%35.3%43.2%50.3%57.7%

Percentages apply to net monthly income (gross minus taxes and mandatory deductions).

Child Support: Complete Guide to Calculations, Modifications & Enforcement

Child support is a court-ordered payment from one parent to the other to help cover the costs of raising children after separation or divorce. All 50 US states use guidelines to standardize child support calculations, though the specific models and formulas vary significantly. Understanding how child support is calculated in your state helps you estimate payments and prepare for court proceedings.

Texas Child Support Calculator

Texas uses a percentage of income model applied to the paying parent's net monthly income. After deducting taxes, Social Security, and Medicare, the court applies: 20% for 1 child, 25% for 2 children, 30% for 3, 35% for 4, and 40% for 5 or more children. Texas caps these percentages once income exceeds approximately $9,200/month net. For higher incomes, the court uses discretion. Texas courts also consider additional expenses such as health insurance and childcare.

California Child Support Calculator

California uses a complex Income Shares formula encoded in state law (Family Code §4055). It considers both parents' net disposable incomes, the percentage of time each parent has physical custody (timeshare), and allowable deductions. California's formula is: CS = K × (HN − (H%) × TN), where K is a combined income factor, HN is the higher earner's net income, H% is their custody percentage, and TN is the combined net income. The result is always calculated using DissoMaster or Xspouse software by courts.

How Shared Custody Affects Child Support

In shared custody arrangements, child support is not eliminated — it is reduced. Most states calculate support as if the non-custodial parent has sole custody, then reduce by the percentage of time they actually have the child. For example, if base support would be $1,000/month and the paying parent has 40% custody, support may be reduced by 40% to $600/month. Some states use a cross-credit or offset method where both parents calculate what they would owe, and the lower-income parent pays the difference to the higher-income parent.

Frequently Asked Questions

Child support is calculated using state-specific guidelines based on one of three models: Income Shares Model (used by most states) — combines both parents' incomes and assigns each a proportional share of child-rearing costs. Percentage of Income Model (used by Texas, Wisconsin, and a few others) — takes a flat percentage of the paying parent's income. Melson Formula (Delaware, Hawaii, Montana) — a more complex version of Income Shares that first reserves income for basic needs. Judges can deviate from guidelines based on special circumstances.
Child support amounts vary widely by state, income, and number of children. As a rough estimate using the percentage model: for 1 child, approximately 17–25% of the non-custodial parent's net income. For 2 children: 25–28%. For 3 children: 29–32%. For 4+ children: 31–40%. Income shares states calculate differently — both parents' incomes are combined, a child-rearing cost table is consulted, and each parent pays their proportional share.
Income Shares Model (majority): Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, West Virginia, Wyoming. Percentage of Income: Texas, Wisconsin, Alaska (hybrid). Melson Formula: Delaware, Hawaii.
Child support calculations typically include all sources of income: wages and salaries, self-employment income, rental income, investment income (dividends, capital gains), Social Security benefits, disability payments, pension and retirement income, bonuses and commissions, overtime (sometimes), workers compensation, and unemployment benefits. Welfare/public assistance and income from a new spouse is generally NOT included.
Yes. Either parent can request a modification when there is a substantial change in circumstances, typically defined as a 10–15% change in income, job loss, significant change in custody arrangement, child's health needs change, or cost of living changes. Most states allow review every 3 years regardless of whether circumstances changed. To modify, file a petition with the court that issued the original order.
In most states, child support continues until the child turns 18 or graduates high school (whichever is later), up to age 19 in some states. Exceptions: if the child is in college (some states require support through college), if the child has a disability requiring ongoing support, if parents agreed to longer support in a settlement. Support can end earlier if the child becomes legally emancipated, marries, joins the military, or becomes self-supporting.
No. Child support payments are neither tax-deductible for the paying parent nor taxable income for the receiving parent under federal law (this changed in 1985 — prior law was different). This differs from alimony paid under pre-2019 divorce agreements, which was deductible for the payer. The child's dependency exemption and Child Tax Credit typically go to the custodial parent, though parents can agree to alternate this.
Enforcement options for unpaid child support include: wage garnishment (automatic withholding from paycheck), tax refund interception, bank account levying, driver's license suspension, professional license suspension, passport denial, credit bureau reporting, contempt of court (fines or jail), property liens, and lottery/prize intercept. Federal law (CSEA) requires all states to enforce child support orders. Back-owed support (arrears) accumulates with interest.
Not necessarily. Even with equal (50/50) physical custody, child support may still be owed if there is a significant income difference between parents. The higher-earning parent may owe support to the lower-earning parent to equalize the standard of living in both households. The amount is typically reduced compared to sole-custody situations. The exact formula depends on your state's guidelines.
Imputed income is income that a court assigns to a parent who is voluntarily unemployed or underemployed. If a parent quits their job or takes a lower-paying position to reduce child support, courts can calculate support based on what the parent could earn rather than what they actually earn. Courts look at the parent's work history, education, skills, and local job market to determine what income to impute.
The paying parent's remarriage generally does NOT reduce child support obligations to children from a prior relationship. The new spouse's income is typically not counted. However, if the receiving parent remarries, courts generally do not reduce child support because the child's needs are from the biological parents. If the paying parent has new children, they may petition for modification based on changed financial circumstances.
Beyond basic child support, courts often order parents to share additional expenses proportionally: health insurance premiums and unreimbursed medical expenses, childcare costs (daycare, after-school care), educational expenses (tuition, books, uniforms), extracurricular activities, and in some states, college expenses. These are typically split according to each parent's percentage of combined income.