Child Support Calculator
A generalized Income Shares estimate — for planning, not a legal filing.
Child Support Calculator
Parents & Children
Add-On Expenses
Estimated Support Order
This uses a generalized Income Shares model similar to the majority of U.S. states. Every state — and some counties — apply their own worksheet, self-support reserve, and deviation factors. Use this for planning only; confirm the exact number with your state's official child support guideline calculator or a family law attorney.
Based on your results — what to do next:
Build a budget around this obligation
A $1,280/mo support payment changes your monthly cash flow — plan needs, wants, and savings around it.
Recheck your take-home pay
Child support isn't taxable to the recipient or deductible to the payer — see how it affects your real monthly take-home.
Rebuild your safety net
With a new $1,280/mo obligation, resize your 3–9 month emergency fund target.
Child support is a court-ordered monthly payment from one parent to the other to cover a child's living, healthcare, and childcare costs. This calculator applies the generalized Income Shares model used by most U.S. states — combining both parents' incomes, applying a guideline percentage, adding childcare and health insurance, and adjusting for parenting-time overnights — to estimate a monthly obligation.
How the Income Shares Model Works
Both parents' gross monthly incomes are combined into one pool. A guideline percentage — which rises with the number of children and tapers at higher income tiers — sets the total "cost of raising the children" that both parents are presumed to owe together.
| Children | Base Guideline % (first $10k combined) |
|---|---|
| 1 child | 18% |
| 2 children | 26% |
| 3 children | 30% |
| 4+ children | 33–37% |
The guideline rate tapers on income above $10,000/month combined (half rate from $10k–$20k, quarter rate above $20k), since higher-income households don't spend proportionally more on a child's basic needs. Every state publishes its own version of this table — the figures above are a national approximation for estimating purposes.
⚠️ Expert Pro-Tip
Overnights are tracked, not estimated. The parenting-time adjustment in most state formulas is based on an actual overnight count from a parenting plan or calendar — not a rough "every other weekend" guess. If you're near a threshold (commonly 25% or 40% of nights), a handful of extra overnights a year can meaningfully change the support number. Keep a written log or shared calendar so the count used in court matches reality.
What This Calculator Can — and Can't — Tell You
Income Shares vs. Percentage of Income
Most states (including California, New York, Colorado, and Illinois) use some version of the Income Shares model modeled here. A minority of states, most notably Texas and Wisconsin, instead use a Percentage of Income model that applies a flat percentage only to the paying parent's income, ignoring the other parent's earnings entirely. If you're in one of those states, this estimate will not match your state's official worksheet.
Add-Ons That Almost Always Apply
Beyond the basic obligation, nearly every state guideline adds work-related childcare costs and the children's portion of health insurance premiums on top, typically split proportionally by income share just like the base amount. Extraordinary medical expenses, private school tuition, and extracurricular costs are handled as case-by-case deviations in most jurisdictions rather than baked into the standard formula.
This Is a Planning Tool, Not a Legal Filing
Courts use official state worksheets with self-support reserves, low-income adjustments, imputed income rules for unemployed or underemployed parents, and local deviation factors that a general calculator cannot fully replicate. Use this tool to understand the mechanics and get a reasonable planning number, then confirm the exact figure with your state's official child support guideline calculator or a family law attorney before relying on it in a filing or negotiation.
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