Child Support Calculator
Disclaimer: This is a rough, generic estimate based on a simplified percentage-of-income guideline. Actual child support is determined by state-specific guidelines and a court order. Not legal advice.
An Illustrative Percentage Model, Not a State Formula
Actual child support in the United States is calculated using state-specific guideline formulas — most states use either an "income shares" model or a "percentage of obligor income" model, each with its own worksheets, deviations, and adjustments for custody time, healthcare, and childcare costs. This calculator does not replicate any specific state's formula. Instead, it applies a simplified, commonly-referenced percentage-of-combined-income guideline purely to illustrate the mechanics of how income shares translate into a support figure.
The Formula
Payor's Income Share = Payor Income ÷ Combined Income
Payor's Support Amount = Total Support Obligation × Payor's Income Share
The guideline percentage applied to combined income scales up with the number of children, reflecting the illustrative assumption used here:
| Number of children | Guideline % |
|---|---|
| 1 | 17% |
| 2 | 25% |
| 3 | 29% |
| 4 | 31% |
| 5 | 33% |
| 6 or more | 35% |
Where This Matters
- Getting a ballpark before consulting an attorney — a rough figure helps frame expectations before a formal calculation using your state's actual guideline worksheet.
- Understanding the income-shares concept — seeing how the payor's share of combined income directly scales their portion of the total obligation illustrates the logic behind most state guideline models, even though the exact percentages differ.
- Preparing questions for a consultation — entering different income and custody scenarios highlights which variables matter most before a formal state-specific calculation.
How to Use This Calculator
- Enter the paying parent's monthly income.
- Enter the other parent's monthly income.
- Enter the number of children.
- Select Calculate for an illustrative monthly support estimate.
Related Calculations
Working through a divorce as well? See the Alimony Calculator, or check the Legal Fee Calculator for representation costs.