Child Support & Alimony Calculator — Estimate Your Payments

Estimate child support and spousal alimony payments based on income, custody arrangement, and number of children. Uses simplified income shares guidelines common across most US states

Support Payment Estimator
Estimate only Not legal advice
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Spousal Alimony (Optional)
Estimated Payments

Enter income and family details to estimate child support and alimony

Frequently Asked Questions
How is child support calculated in the US?

Most states use the "income shares" model: both parents' incomes are combined, a table determines the total child support obligation based on combined income and number of children, then each parent pays their proportional share. The non-custodial parent typically pays their share to the custodial parent. Some states (like New York) use a flat percentage of the non-custodial parent's income.

What percentage of income goes to child support?

General guidelines vary by state and number of children. Rough estimates: 1 child: 17-20% of gross income, 2 children: 25-28%, 3 children: 29-33%. These are simplified — actual calculations consider both parents' incomes, childcare costs, health insurance, and custody time split.

How long does spousal alimony last?

Duration typically depends on the length of marriage. Common guidelines: marriages under 10 years get alimony for 30-50% of the marriage length. Marriages of 10-20 years: 60-70% of the marriage length. Marriages over 20 years may result in permanent alimony in some states. Many states are moving toward time-limited "rehabilitative" alimony.

Can child support be modified?

Yes, child support can be modified if there's a "material change in circumstances" — job loss, significant income change (up or down), change in custody arrangement, or child's needs changing. You must file a motion with the court; you can't just stop paying. Most states allow modification reviews every 2-3 years.

What is the difference between child support and alimony?

Child support is money paid for the children's needs (food, housing, education, healthcare) and ends when the child turns 18-21 depending on the state. Alimony (spousal support) is money paid to the lower-earning spouse to maintain their standard of living after divorce, and duration varies based on marriage length and state law.

Is child support tax-deductible?

No. Since 2019 (Tax Cuts and Jobs Act), child support is not tax-deductible for the payer and not taxable income for the recipient. Alimony for divorces finalized after December 31, 2018 follows the same rule — not deductible and not taxable. Divorces finalized before 2019 may still follow the old rules where alimony was deductible.

Child Support & Alimony Calculator — Understanding Family Support Payments

Divorce and separation involve complex financial calculations. Child support ensures children maintain a similar standard of living in both households, while spousal alimony helps the lower-earning spouse transition to financial independence. This calculator provides estimates based on common US guidelines — actual amounts are determined by state law and court discretion.

How Child Support Is Calculated

The income shares model, used in about 40 states, combines both parents' gross incomes and uses a lookup table to determine the total child support obligation. Each parent pays their proportional share based on income. The non-custodial parent's share is typically paid to the custodial parent. Additional expenses like childcare, health insurance, and extraordinary medical costs are split proportionally on top of the base amount.

Custody time affects payments. Many states reduce child support when the non-custodial parent has significant parenting time (typically over 20-30% of overnights). The logic is that the parent is already covering housing, food, and other costs during their custody time. A 50/50 custody split may reduce or eliminate child support payments, depending on the income differential.

Spousal Alimony Guidelines

Alimony formulas vary by state, but a common simplified approach calculates alimony as 30-35% of the difference between the spouses' gross incomes. Duration is typically linked to marriage length: short marriages (under 10 years) may get alimony for 30-50% of the marriage duration, medium marriages (10-20 years) for 60-70%, and long marriages (20+ years) may qualify for permanent alimony in some jurisdictions.

Factors courts consider include each spouse's earning capacity, age and health, standard of living during marriage, contributions to the marriage (including homemaking), education and employability, and the division of marital property. Alimony can be modified if circumstances change significantly, and it typically ends upon the recipient's remarriage or cohabitation.

Important Disclaimers

This calculator provides estimates only and should not be relied upon as legal advice. Child support and alimony calculations vary significantly by state, and courts have discretion to deviate from guidelines based on specific circumstances. Consult a family law attorney in your state for accurate calculations and legal guidance.

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