Child Support Calculator
Estimate monthly child support payments using the Income Shares Model, the standard formula used in most US states.
Built for general U.S. informational use. Local rules, court practices, and case facts can change the result.
Child Support Calculator
Fill in the fields below to get your estimate
The Income Shares Model Explained
Most states use the "Income Shares Model" to calculate child support. The philosophy is that a child should receive the same proportion of parental income they would have received if the parents lived together.
- Combine Income: Parent A's income + Parent B's income = Total Combined Income
- Determine Basic Support: Use a state-provided economic table to figure out the basic child support obligation based on the combined income and number of children.
- Proportional Share: Divide the basic support obligation between the parents based on their share of the combined income. (e.g., if Parent A earns 60% of the total income, they are responsible for 60% of the obligation).
- Add-ons: Add health insurance, childcare, and extraordinary expenses, distributed proportionally.
- Parenting Time Adjustment: Adjust the paying parent's obligation downwards if they host the child for a substantial number of overnights.
This calculator provides a generalized estimate. State-specific tables vary widely. Courts may also deviate from guidelines if strict application is unjust. Consult a family attorney or your state's child support agency for accurate numbers.
How this estimate works
This calculator uses a generalized income-shares approach: combined parental income, number of children, add-on costs, and parenting time all affect the estimated support obligation. It is designed for orientation before using a state worksheet.
Inputs this page weighs
- Both parents' gross monthly income.
- Number of children covered by the estimate.
- Child healthcare and work-related childcare costs.
- Parenting-time or overnight percentage.
How to verify the result
Use the result beside your state child-support worksheet or agency calculator, because income definitions, deductions, caps, and parenting-time adjustments vary by state.
How to use this Child Support Calculator well
Best used when
- Testing how income changes, overnights, and add-on costs affect a support estimate.
- Building a first draft before comparing it with a state worksheet.
- Preparing documents for a family law consultation or agency conversation.
Be careful if
- Gross income, variable pay, and self-employment income are easy to misstate.
- Parenting-time adjustments vary by state and by how overnights are counted.
- Healthcare and childcare costs often move the number more than expected.
Questions to answer next
- Are you using real income documents rather than memory-based estimates?
- Do you know the actual overnight schedule that the court or worksheet will use?
- What state-specific deductions, caps, or add-on rules may apply locally?
Before you use a family law calculator
What to gather first
- Recent pay stubs, tax returns, and proof of recurring income or bonuses.
- Health insurance costs, childcare costs, and any existing court orders.
- A realistic parenting schedule or overnight calendar if custody affects the estimate.
Why results may change
- State guidelines may use different income definitions, deductions, or formula tables.
- Judges can depart from the standard worksheet when a strict formula would be unfair.
- Support and property estimates often change once full financial disclosures are exchanged.
Best next step
- Save your estimate and compare it with your actual monthly documents.
- Make a list of expenses that are easy to miss, such as healthcare, childcare, and debts.
- Verify the result with a state-specific worksheet, mediator, or family law attorney.