Estimate California child support using the Income Shares Model (Dissomaster). Free, private, and updated for 2026.
Legal Disclaimer
These calculators provide estimates for educational purposes only. Child support and family law calculations vary significantly by state, judge, and individual circumstances. Results are not legal advice and do not create an attorney-client relationship. Consult a licensed family law attorney in California for advice specific to your situation.
California uses the Income Shares Model (Dissomaster) to determine child support obligations. California uses a detailed income shares formula under Family Code § 4055, implemented through software called Dissomaster or X-Spouse. The formula accounts for each parent's net disposable income, time-share percentage, tax filing status, and deductions. California child support is considered the highest in the nation for its complexity.
California uses net (after-tax) income and accounts for health insurance, mandatory union dues, and other deductions. The formula is: CS = K × (HN − (H%)(TN)) where K is a constant based on time-share and income, HN is the higher net income, H% is higher earner's percentage of parenting time, and TN is total net income.
California has an official Guideline Calculator available through the California Courts website (courts.ca.gov). Courts use Dissomaster or X-Spouse software for official calculations.
Alex earns $5,500/month gross income. Jordan earns $3,200/month. They have 2 children in California. Alex has primary custody; Jordan has standard visitation (every other weekend, approximately 73 overnights/year).
This example uses approximate calculations. Actual California child support requires the official Income Shares Model (Dissomaster) worksheet or software and should be verified with a licensed family law attorney or the court.
Both Parents' Income
California's Income Shares Model (Dissomaster) combines both parents' incomes to determine the total family resources available for the children. A higher combined income results in higher support — reflecting the idea that children should benefit from the family's overall financial resources regardless of which parent they primarily reside with.
Custody and Parenting Time
California adjusts child support based on the amount of parenting time each parent has. More overnight time with the paying parent generally reduces the support obligation — reflecting that the paying parent directly absorbs the children's costs during their parenting time. California uses net (after-tax) income and accounts for health insurance, mandatory union dues, and other deductions.
Health Insurance and Childcare
Health insurance premiums for the children and work-related childcare costs are added to the basic child support obligation in California. The cost is typically split proportionally based on each parent's share of combined income. These add-ons can significantly increase the total support obligation, particularly in cases with high childcare or health insurance costs.
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California uses the Income Shares Model (Dissomaster) to calculate child support. California uses a detailed income shares formula under Family Code § 4055, implemented through software called Dissomaster or X-Spouse. The guideline amount is the starting point, but courts may deviate based on special circumstances such as a child's extraordinary medical needs, travel costs for visitation, or significantly different financial situations from the guideline assumptions. Always confirm your specific calculation with a California family law attorney.
California uses both parents' gross monthly income as the starting point for child support calculations, combining them into a total family income figure. Courts may also impute income to a parent who is voluntarily underemployed or unemployed without good cause — meaning they may be held to what they could earn rather than what they actually earn.
No. In California, shared custody reduces but does not eliminate child support in most cases. When both parents share custody equally, California typically uses an offset method where each parent's guideline support is calculated and the higher earner pays the difference. The goal is to ensure the children maintain a similar standard of living in both households. If incomes are nearly equal, the resulting payment may be very small, but it rarely drops to zero unless incomes are identical.
In California, child support generally continues until the child reaches the age of majority (typically age 18), graduates from high school, or is otherwise emancipated — whichever occurs later up to the state maximum. Courts may also continue support for adult disabled children who cannot support themselves. Support does not automatically end — the paying parent must file for termination when the child ages out or becomes emancipated.
Yes. California child support can be modified when there is a substantial change in circumstances. Most states, including California, require that the new calculated amount differ from the existing order by at least 15% — or that three years have passed since the order was entered, triggering an automatic review. Changes that typically qualify include significant income changes for either parent, a change in custody arrangement, a child's new medical needs, or loss of health insurance coverage. Modifications require filing a motion with the family court — the original order remains in effect until a new order is entered.