Quick answer: California uses a statewide formula, CS = K[HN − (H%)(TN)], not a table. It starts from each parent’s net monthly disposable income and the share of time the higher earner has the children. K, the share of income allocated to support, depends on the parents’ combined net income and the timeshare, and the result is multiplied by 1.6 for two children, 2 for three and more for larger families. The higher earner pays a positive result and the lower earner pays a negative one. Child care and uninsured health costs are added and shared in proportion to income. The amount is presumed correct.
How the California formula works
The calculator applies Family Code 4055 as it has read since September 1, 2024:
- Net disposable income. Each parent’s gross income less the deductions allowed by Section 4059, such as income taxes, FICA, mandatory union dues and retirement, health insurance premiums and support paid to others. You enter the monthly result; see what income counts in California.
- HN, TN and H%. HN is the higher earner’s net income, TN the total of both, and H% the approximate share of time the higher earner has primary physical responsibility for the children.
- K. One plus H% (if H% is 50% or less) or two minus H% (if more), times a fraction based on TN: 0.165 + TN/82,857 up to $2,900; 0.131 + TN/42,149 from $2,901 to $5,000; 0.25 from $5,001 to $10,000; 0.10 + 1,499/TN from $10,001 to $15,000; and 0.12 + 1,200/TN above $15,000.
- Children. Multiply by 1.6 (two children), 2 (three), 2.3 (four), 2.5 (five), 2.625 (six) and up to 2.86 for ten.
- Add-ons. Employment-related child care and reasonable uninsured health costs are ordered as additional support and divided in proportion to net incomes after the basic support is first computed.
The step-by-step version, with a worked example, is in how the California child support formula works. How the timeshare changes the result is in timeshare and California child support.
Low incomes
If the obligor’s net disposable income is less than what full-time minimum wage earns gross in a month (40 hours a week, 52 weeks a year), there is a rebuttable presumption of a low-income adjustment. It can reduce support by up to the guideline amount times the fraction (minimum-wage income minus the obligor’s net income) divided by the minimum-wage income. The field above is pre-filled with the current statewide minimum wage ($16.90 an hour); update it if the wage changes.
When the presumption can be rebutted
The formula amount is presumed to be the correct amount of child support. A court can order a different amount only on specific findings under Section 4057(b), such as a stipulation, an extraordinarily high income where the formula amount would exceed the children’s needs, a parent not contributing at a level commensurate with that parent’s custodial time, or other special circumstances. The calculator does not apply those findings, spousal support adjustments or hardship deductions.
Child support across California
The guideline is statewide and applies in every superior court, from Los Angeles, San Diego, San Jose, San Francisco, Sacramento or Fresno. Because California’s formula uses net income, taxes matter: courts and the Department of Child Support Services use software to compute net disposable income from gross income and the parents’ tax status. This calculator takes the net figures you already have.
Frequently asked questions
How is child support calculated in California?
California uses the statewide formula CS = K[HN - (H%)(TN)] in Family Code 4055. It starts from both parents' net monthly disposable income and the share of time the higher earner has the children, then multiplies by a factor that rises with the number of children.
What is net disposable income in California?
Gross income minus the deductions in Family Code 4059, including income taxes, FICA, mandatory union dues and retirement, health insurance premiums and support actually paid for others under a court order.
Does California child support depend on custody time?
Yes. H%, the approximate share of time the higher earner has the children, is part of the formula, so support falls as the higher earner's time rises toward half.
Who pays child support in California?
If the formula result is positive, the higher earner pays the lower earner; if it is negative, the lower earner pays the absolute value to the higher earner.
Is the California guideline amount mandatory?
It is presumed to be the correct amount. The presumption can be rebutted by evidence that applying the formula would be unjust or inappropriate for one of the reasons listed in Family Code 4057(b).