Child Support Estimate Calculator
Rough estimate of monthly child support using a simplified income-shares model: combined income, a support percentage, and each parent's income share.
How to use this tool
- Enter paying parent monthly gross income, receiving parent monthly gross income and support obligation % of combined income in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your estimated monthly support and the full breakdown beneath it.
This is an estimate, not legal advice. Laws vary by jurisdiction and individual circumstances. Consult a qualified attorney before making any legal decisions.
This is a rough estimate only, not legal advice. Child support is calculated by courts using state-specific guidelines (income shares, percentage of income, or Melson formula) and considers many additional factors including custody arrangement, health insurance, childcare costs, and special needs. Only a court order establishes enforceable child support obligations.
Formula
Combined income = paying parent income + receiving parent income
Paying parent income share = paying income ÷ combined income
Total obligation = combined income × support % ÷ 100
Estimated monthly support = total obligation × paying parent income share
How it works
This calculator uses a simplified income-shares model: it determines the total child-support obligation as a percentage of both parents' combined monthly gross income, then assigns the paying parent's portion proportionally to their share of that combined income. The income-shares model is the framework used by most U.S. states, but actual court orders involve additional factors including custody time, child-care costs, health insurance premiums, and state-specific guideline tables. This tool produces a rough planning estimate only and is not a substitute for legal advice.
Worked example
Worked example
- Combined income = $4,000 + $6,000 = $10,000/month
- Paying parent income share = $4,000 ÷ $10,000 = 40%
- Total obligation = $10,000 × 20% = $2,000/month
- Estimated support = $2,000 × 40% = $800/month
Combined income $10,000; paying parent share 40%; estimated monthly child support $800.
Key terms
- Income-shares model
- A child-support calculation approach that estimates the amount parents would have spent on the child if living together, then divides that obligation proportionally by each parent's income.
- Combined income
- The sum of both parents' monthly gross incomes, used as the base for calculating the total support obligation.
- Income share
- Each parent's percentage contribution to the combined income, determining their pro-rata share of the total child-support obligation.
- Gross income
- Pre-tax, pre-deduction earnings from all sources, typically used in child-support calculations rather than net income.
- Guideline support
- The amount produced by a state's statutory formula or schedule, which courts use as the presumptive child-support order subject to deviation for unusual circumstances.
Frequently asked questions
- How is child support actually calculated?
- Every US state has its own child support guidelines mandated by federal law. Most use an 'income shares' model that starts with combined parental income and applies a schedule based on the number of children. Courts can deviate from guidelines for special circumstances.
- Does custody arrangement affect the amount?
- Yes, significantly. Shared physical custody (where each parent has the child a substantial portion of the time) typically reduces the support obligation because both parents incur direct childcare costs.
- Can child support be modified?
- Yes. Either parent can petition for modification if there is a substantial change in circumstances, such as a significant change in income, change in custody, or the child's needs changing.