California Child Support Calculator
Estimate the guideline amount under California's statewide uniform guideline (the formula behind Dissomaster). This simplified approximation uses combined net income — free, instant, no data stored.
Guideline Estimate
California uses the statewide uniform guideline (the formula behind Dissomaster). This simplified estimate applies approximate percentages of combined net income (gross × 0.78) and allocates the obligation by income share. The actual Dissomaster calculation includes taxes, deductions, timeshare, and add-ons; courts order the guideline amount absent special circumstances.
How California calculates child support
California uses a statewide uniform guideline (Family Code §§4050–4076), the same formula behind the Dissomaster and Xspouse programs used by courts and attorneys. The guideline is presumed correct, and courts order it unless a party proves a legal reason to deviate.
- Estimate each parent's net disposable income (gross less taxes, mandatory deductions, health insurance, and certain other items). This calculator approximates net as 78% of gross.
- Apply the guideline percentage for the number of children (25% for 1, up to 50% for 6).
- Allocate the total obligation between parents by each parent's share of net income.
California guideline percentages (approximate)
| Children | Guideline percentage of combined net income |
|---|---|
| 1 | 25% |
| 2 | 32% |
| 3 | 38% |
| 4 | 43% |
| 5 | 47% |
| 6 | 50% |
What the full formula includes
The actual Dissomaster calculation accounts for each parent's actual tax filing status, deductions, mandatory retirement contributions, health insurance premiums, the parents' timeshare with the child, and add-ons such as childcare and uninsured medical costs. This page is a simplified approximation — use the court's official calculator or an attorney for a precise figure.
Frequently asked questions
Does California use Dissomaster? Dissomaster is a software program that implements the statewide uniform guideline. Courts widely accept its output, but the guideline itself is set by statute, not by the software.
How long does child support last? Generally until the child turns 18, or 19 if still a full-time high school student living with a parent and not self-supporting.
Can the amount be modified? Yes — on a showing of changed circumstances (income, custody, or the child's needs) the court can modify support.