Child Support Calculator
Estimate child support — Income Shares (40 states), Percentage of Income (AK/IL/MS/NV/ND/WI), Melson (DE/HI/MT). 17-40% of income depending on children count. Modification + enforcement.
How much is child support for 1, 2, 3+ children? 1 child: 17-25% of income typical (NY: 17%, CA: 25%, TX: 20%). 2 children: 25-33%. 3 children: 29-36%. 4 children: 31-40%. 5+: 33-40%. Applied to gross or net depending on state.
⚖ 3 state formula models. 1 child: 17-25% of income. 2 children: 25-33%. 3: 29-36%. 4+: 31-40%. Wage garnishment up to 50-65%.
Your Case Details
Answer a few questions to see your estimated range.
Approximate gap between higher-earner and lower-earner.
Estimated Monthly Support
$840 — $1,560
State formulas vary significantly. This estimate uses national averages — your state's guidelines may produce a different number.
Editorially Reviewed — Content reviewed for accuracy using published legal research, government data, and verified court records. See our methodology
Reviewed by Leonard Goldberg, Editor · Last updated
Child Support — How Courts Calculate
US child support uses one of three state-level formulas: (1) Income Shares Model (~40 states incl. CA, FL, NY, TX) — combines both parents' incomes, calculates total obligation from a schedule, splits proportionally by each parent's share. (2) Percentage of Income (6 states: Alaska, Illinois, Mississippi, Nevada, Wisconsin, North Dakota) — only non-custodial parent's income considered. (3) Melson Formula (3 states: Delaware, Hawaii, Montana) — most complex; preserves self-support reserve for each parent first.
Typical percentages (applied to gross or net income per state rules): 1 child 17-25%; 2 children 25-33%; 3 children 29-36%; 4 children 31-40%; 5+ children 33-40%. Adjustments for: overnight custody split, childcare costs, health insurance, extraordinary expenses (special needs, private school).
Duration: default age 18 or high school graduation (whichever later) in most states. Age 21 states: Mississippi, New York. Age 23 (college): Massachusetts if enrolled. Age 20 secondary schooling: Minnesota. Disabled children: may continue indefinitely.
Child Support FAQs
How is child support calculated in my state?
Depends on which model your state uses. Income Shares (40+ states): combines both parents' incomes, applies to state schedule, each parent pays proportional share. Your share = (your income ÷ combined income) × total obligation. Percentage of Income (6 states): flat % of non-custodial parent's income. Melson (3 states): preserves self-support reserve first, then distributes. Every state has an online calculator — use it for preliminary estimate.
How much is child support for 1, 2, 3+ children?
1 child: 17-25% of income typical (NY: 17%, CA: 25%, TX: 20%). 2 children: 25-33%. 3 children: 29-36%. 4 children: 31-40%. 5+: 33-40%. Applied to gross or net depending on state. Adjustments for overnight custody split, healthcare, childcare. Use your state's official calculator — variances by state are substantial.
What income counts for child support?
Gross income in most states. Includes: wages, salaries, tips, commissions, overtime, bonuses, self-employment income, rental income, investment income, retirement distributions, Social Security (except SSI), unemployment. NOT counted: public assistance, child support received for other children. Imputed income: voluntarily underemployed parents may be imputed to earning capacity — court treats them as earning what they COULD earn, not what they claim.
How do I modify child support?
File motion for modification in court that issued original order. Show 'substantial change in circumstances' — typically 15-20% income change or $50-$100/month differential. Common grounds: (1) job loss, (2) income increase, (3) additional children, (4) custody schedule change, (5) child's medical needs, (6) incarceration. Modifications not retroactive — support owed at current rate until court modifies. File immediately on income change to avoid arrears accumulation.
What if my ex won't pay child support?
Multiple enforcement tools: Income withholding (usually automatic — contact state child support enforcement agency to set up). Tax refund intercept: federal + state. Passport denial: $2,500+ arrears. License suspension: driver + professional. Liens: real estate, bank accounts. Contempt of court: jail time possible for willful non-payment. State CSED (Child Support Enforcement Division) handles most enforcement for free. Federal OCSE coordinates interstate cases.
Can I stop paying when my child turns 18?
Usually 18 or high school graduation (whichever later) in most states. Exceptions — support continues: Mississippi + NY (age 21); Massachusetts (age 23 if enrolled in college); Minnesota (20 if still in secondary school); Indiana (19 unless in school). Disabled children: may continue indefinitely. You MUST go to court to terminate — do not unilaterally stop paying. Your state's child support enforcement agency can process termination.
Does child support change if I have more children with a new partner?
New children can trigger modification — your income is now supporting additional dependents. Most states adjust support downward by ~10-15% per additional child in your new household (when petitioning to modify). However, this is not automatic — requires motion to modify. Conservative strategy: file immediately after new child's birth. NOT a basis to unilaterally reduce payments without court order.
How does overnight custody affect child support?
Significant reduction with substantial overnights. Most income-shares states apply adjustments starting at 20-25% overnight split. Formula often: support obligation × (1 - overnight_percentage × adjustment_factor). Example: 30% overnight custody may reduce support 20-30%. 50/50 custody may reduce support dramatically — higher-earner pays only offset of income difference. Document overnights meticulously — defense will challenge alleged percentages.
State Child Support Calculators
Each state sets its own guideline model — these calculators apply the state-specific rules: