Child Support Estimator
Estimate child support payments based on both parents' income, number of children, and custody arrangement.
Child Support Estimator
Calculator
Adjust values & calculateEnter your values below. Every result is computed in your browser — no data is sent to any server.
Formula: Support = (Combined Income × Child %) × Non-Custodial Income Share × Custody Adjustment + Additional Costs
Worked example — Estimated monthly payment: ~$668 from non-custodial parent
Formula
Support = (Combined Income × Child %) × Non-Custodial Income Share × Custody Adjustment + Additional Costs
This estimator uses a simplified Income Shares Model. The combined parental income determines the basic child support obligation based on the number of children. The non-custodial parent's share is proportional to their income, adjusted for the custody split. Additional childcare and health insurance costs are added.
Worked Examples
Example 1: Standard Custody Arrangement
Problem:Parent 1 earns $60,000/year (custodial, 80% custody), Parent 2 earns $40,000/year, 2 children, $500/month childcare, $200/month health insurance.
Solution:Combined Income = $100,000 Child Support % (2 children) = 25% Basic Obligation = $100,000 × 25% = $25,000/year = $2,083/month Parent 2's income share = 40% Custody adjustment = 60% (80% vs 50%) Estimated Payment = ($2,083 + $700) × 40% × 60% ≈ $668/month
Result:Estimated monthly payment: ~$668 from non-custodial parent
Example 2: 50/50 Custody Split
Problem:Parent 1 earns $80,000/year, Parent 2 earns $50,000/year, 1 child, 50/50 custody, no additional costs.
Solution:Combined Income = $130,000 Child Support % (1 child) = 17% With 50/50 custody, the adjustment factor approaches zero The higher earner may still owe a small equalization payment
Result:With equal custody, support obligation is minimal or zero
Frequently Asked Questions
How is child support calculated?
Most states use one of two models: the Income Shares Model (used by about 40 states) or the Percentage of Income Model. The Income Shares Model combines both parents' incomes, determines the total child support obligation based on the number of children, and then allocates the obligation proportionally based on each parent's share of the combined income. Custody arrangements, childcare costs, and health insurance premiums are factored in as adjustments.
What factors affect child support amounts?
Key factors include: both parents' gross or net income, number of children, custody and visitation schedule, childcare expenses, health insurance costs, special needs of the child, other child support obligations, and the standard of living during the marriage. Some states also consider the age of the children, education costs, and extraordinary expenses. Each state has its own guidelines and formulas.
Can child support be modified?
Yes, child support can be modified if there is a significant change in circumstances. Common reasons include: substantial change in either parent's income (job loss, raise, or new job), change in custody arrangement, change in the child's needs (medical or educational), remarriage or new children, or changes in childcare or health insurance costs. You typically need to file a motion with the family court to request a modification.
How does custody split affect child support?
Custody arrangements significantly impact child support calculations. In most states, the parent with less custody time (non-custodial parent) pays support to the custodial parent. In a 50/50 custody arrangement, the higher-earning parent typically pays a reduced amount to the lower-earning parent. Some states provide specific formulas for shared custody that reduce the obligation based on the number of overnight stays each parent has.
How long does child support last?
Child support typically continues until the child turns 18 (or 19 in some states), graduates from high school, becomes emancipated, joins the military, or gets married. Some states extend support through college (up to age 21 or 23). Support for children with disabilities may continue indefinitely. The specific age and conditions vary significantly by state, so check your state's laws or consult an attorney.
What is the difference between the Income Shares Model and the Percentage of Income Model?
Income Shares starts from both parents' combined income, looks up what a household at that level typically spends on children, and splits that obligation in proportion to each parent's income share. Percentage of Income ignores the custodial parent's earnings and applies a set percentage to the non-custodial parent's income alone. Income Shares responds to changes in either parent's earnings, while Percentage of Income is simpler to administer but can produce very different results where incomes are unequal.
Should gross or net income be entered into a child support estimate?
It depends on the state model the estimate is meant to approximate. Some guidelines run on gross income and build tax effects into the table itself, while others require net income after taxes, mandatory retirement contributions, and existing support orders for other children. Mixing the two produces a materially wrong figure. Use one basis consistently for both parents, and check which basis your jurisdiction's official worksheet uses before relying on the result.
How are childcare and health insurance costs shared between the parents?
Work-related childcare and the children's share of a health insurance premium are usually treated as add-on expenses on top of the basic obligation. They are added to the total and then apportioned by income share, with credit given to whichever parent actually pays the bill. This means a parent who carries the family health plan can see their net payment fall, and a change in daycare arrangements alone can be grounds to revisit the order.
Why can an estimator's output differ from the amount a court actually orders?
An estimator applies a simplified national model, while courts apply a specific state guideline table and then consider deviation factors: extraordinary medical or educational expenses, a parent's other support obligations, imputed income, split custody, and a low-income self-support reserve. Judges can depart from the guideline figure with written findings. Treat the output as an order of magnitude for planning and budgeting, not as a prediction of the number a judge will sign.
What is imputed income and when do courts apply it to a support calculation?
Imputed income is earning capacity attributed to a parent who is voluntarily unemployed or working below their demonstrated ability, so support is based on what they could reasonably earn rather than what they report. Courts look at work history, qualifications, health, and prevailing local wages. Imputation is generally not applied where unemployment is involuntary, where a disability limits work, or where the parent is the primary caregiver for a very young child.
References
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
Related Calculators
🧮Child Support Calculator
Estimate child support payments based on both parents incomes, custody, and number of children.
🧮Bail Amount Estimator
Estimate bail amounts based on charge severity, criminal history, and jurisdiction guidelines.
🧮Alimony Calculator
Estimate spousal support payments based on income disparity, marriage length, and state guidelines.
🧮Legal Fee Split Calculator
Calculate legal fee split with interactive inputs and clear steps.
🧮Contract End Date Calculator
Calculate contract end date with inputs, formulas, and instant results.
🧮Notice Period Calculator
Calculate notice period with inputs, formulas, and instant results.
🧮Prorated Rent Calculator
Calculate prorated rent with inputs, formulas, and instant results.
🧮Actual/360 Day Count Calculator
Calculate day count actual360calculator with inputs, formulas, and instant results.