How to use Child Support Calculator
The child support calculator estimates monthly payments using the Income Shares model — the method used by the majority of US states. It combines both parents' incomes to determine a base obligation, then allocates each parent's share proportionally. Results are estimates; actual orders are set by a family court.
- Enter both parents' gross monthly incomes.
- Select the number of children.
- Choose the custody arrangement (physical custody split).
- Add extraordinary expenses (health insurance, childcare, medical).
- Review the estimated obligation and which parent pays how much.
Your data never leaves your device — 100% private processing.
The Income Shares model
Most US states use the Income Shares model: both parents' incomes are added, a base obligation is looked up from a state table (representing what intact families spend on children at that income level), and each parent pays their proportionate share. The non-custodial parent's share is paid directly; the custodial parent's share is assumed to be spent directly on the child. Extraordinary expenses (health insurance, childcare, tutoring) are added on top.
| Combined gross income | 1 child | 2 children | 3 children |
|---|---|---|---|
| $3,000/mo | ~$530 | ~$780 | ~$960 |
| $5,000/mo | ~$780 | ~$1,140 | ~$1,380 |
| $7,500/mo | ~$1,060 | ~$1,540 | ~$1,830 |
| $10,000/mo | ~$1,300 | ~$1,880 | ~$2,230 |
Modifications, deviations and enforcement
Courts can deviate from guidelines for high income, disabled children, shared-custody situations (50/50) or extraordinary needs. Child support orders can be modified when circumstances change substantially (income change > 15%, change in custody, new children, etc.). Non-payment can result in wage garnishment, licence suspension, contempt of court and tax-refund interception. Always consult a family law attorney for your specific state's guidelines.
Worked examples
Combined $5,000/mo, 1 child (illustrative)
Inputs: base ~$780 × payor 60% income share
Result: ≈ $468/mo — your state guidelines differ
Combined $7,500/mo, 2 children (illustrative)
Inputs: base ~$1,540 × 55% payor share
Result: ≈ $847/mo — illustrative; state tables vary
Adding childcare expense (illustrative)
Inputs: base $468 + 60% × $800 childcare
Result: ≈ $948/mo — confirm with your state agency
Glossary
- Income Shares
- A child support model combining both parents' incomes to determine total obligation.
- Non-custodial parent
- The parent who does not have primary physical custody; typically pays support.
- Extraordinary expenses
- Work-related childcare, uninsured medical costs, and special educational needs added to base support.
- Modification
- A court-ordered change to the support amount following a material change in circumstances.
Related reading
Frequently Asked Questions
Why use Child Support Calculator?
- Applies the Income Shares model to combine both parents' incomes and allocate each party's proportionate share
- Adjusts the base obligation for actual custody split percentages rather than assuming a 0/100 arrangement
- Adds extraordinary expenses — childcare, health insurance, medical — on top of the base support obligation
- Displays each parent's individual payment amount so both parties can verify the allocation logic
Common use cases
- Estimate monthly child support before a custody hearing to enter negotiations with realistic expectations
- Recalculate the obligation when one parent receives a significant salary increase or changes employment
- Model how shifting from sole custody to a 50/50 shared arrangement changes the monthly payment
- Add health insurance premiums and childcare costs to understand the full financial support picture
- Cross-check a proposed settlement figure against Income Shares guidelines before signing an agreement
Get weekly tool tips & updates
New tools, power-user tips, and productivity hacks — delivered free every Friday.
No spam, ever. Unsubscribe with one click.
Related Insurance
Term Life (DIME) Calculator
Calculate how much life insurance you need using the DIME method. Enter your debt, income, mortgage, and education costs to find the right coverage amount.
Disability / Income Protection Calculator
Calculate how much disability insurance coverage you need. Enter monthly income, expenses, and existing coverage to find your income protection gap.
Life Insurance Calculator
Calculate how much life insurance coverage you need using the DIME method. Accounts for income, mortgage, debts, and children's education.
Loan Calculator
Calculate your loan monthly payment, total interest, and payoff. Compare rates and terms instantly with this free online personal loan calculator.
Percentage Calculator
Calculate percentages instantly. Find what X% of a number is, what percentage X is of Y, or calculate percentage change.
Personal Injury Settlement Estimator
Estimate your personal injury settlement value. Enter medical bills, lost wages, pain and suffering multiplier, and liability percentage for a settlement range.
Explore all Insurance.