Free · No Sign-Up · Income Shares Model · 2026
Child Support Calculator 2026
Estimate monthly child support payments using the real formulas applied by US courts — based on income, custody split, and number of children.
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Child Support Calculator
Income Shares Model · 41 States
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Gross, before taxes$
Estimated if unknown% of nights per year
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$
Estimated Monthly Payment
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Per month · Income Shares Model
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Per Year
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Your Share
$0
Base Obligation
⚖️ Estimate only. Actual orders vary by state and judge. Consult a family law attorney.
How Child Support Is Calculated in the US (2026)
Most US states use the Income Shares Model: both parents’ gross incomes are combined, a base obligation is set by state schedule, then split proportionally based on income share. Work-related child care and health insurance are added on top.
Percentage Guidelines by Number of Children
| Children | % of Combined Income | Notes |
|---|---|---|
| 1 Child | 17% | Standard baseline |
| 2 Children | 25% | Most common |
| 3 Children | 29% | Diminishing returns |
| 4 Children | 31% | Cap begins |
| 5+ | 35%+ | Varies by state |
Example: Parent A earns $5,000/mo, Parent B earns $3,000/mo. Combined = $8,000. For 2 children: $8,000 × 25% = $2,000. Parent A’s share = 62.5% = $1,250. Adjusted for 30% custody ≈ $1,050/month.
Factors That Affect the Amount
- Health insurance premiums paid for children
- Work-related child care costs
- Educational and extraordinary medical expenses
- Other children the paying parent supports
- Parenting time percentage
Frequently Asked Questions
Can child support be modified after it is set?
Yes. Either parent can petition for modification with a substantial change in circumstances — typically 15–25% income change, custody change, or change in child’s needs. Courts review every 3 years.
Does the new spouse’s income count?
In most states, no. The obligation is based solely on the biological parents’ incomes. A new spouse’s income is not counted unless the paying parent voluntarily reduces their own income.
Until what age is child support paid?
Most states: until age 18 or high school graduation (whichever is later, up to 19). Some states extend to 21 or 23 for college students.
Is child support taxable?
No. Not deductible for the payer, not taxable income for the recipient. It is a transfer for the child’s benefit.
What happens if support is not paid?
Consequences include wage garnishment, bank levies, license suspension, tax refund interception, passport denial, and possible jail time.
Related Calculators
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- Child Custody Calculator — Custody arrangement evaluator