California uses a formula, not a judge's discretion
California child support is calculated using a statewide formula set by law. The formula takes both parents' gross income, the amount of time each parent spends with the child, and the number of children involved, then produces a dollar amount. A judge does not decide the amount based on what seems fair — they apply the formula unless both parents agree to something different in writing.
The formula itself is written into California Family Code Section 4055. Every county court uses the same formula. What changes from case to case is the income figures you plug in and how much time each parent has the child.
You can calculate the amount yourself using the state's worksheets, or you can ask the court to do it. Many people use online calculators built on the formula, though those are only estimates — the official calculation happens when you file paperwork with the court or when a judge makes an order.
Key Takeaways
- California's formula multiplies a combined parental income figure by a percentage that depends on how much time each parent spends with the child.
- Gross income includes wages, self-employment earnings, rental income, and some benefits, but the definition varies by income source.
- The time-share percentage (how many overnights each parent has) directly affects the formula result — more time with the paying parent lowers the payment.
- You can use the state's official worksheet or an online calculator to estimate the amount, but the court's calculation is what legally matters.
- If both parents agree on a different amount in writing, a judge can approve it instead of using the formula.
What income counts in the California formula
The formula starts with gross income, which is broader than take-home pay. Gross income includes wages before taxes, self-employment net income (business revenue minus business expenses), rental income, interest and dividends, pension and retirement distributions, social security, unemployment insurance, disability insurance, and workers' compensation.
Some income does not count. Child support received from another case, means-tested public benefits (like CalFresh or CalWORKs), and Supplemental Security Income (SSI) are excluded. If a parent is not working, the court can assign "imputed income" — a figure based on what they could earn — but only if the parent is deliberately underemployed or unemployed to avoid support.
If you are self-employed, you report net self-employment income (revenue minus ordinary business expenses). You will need tax returns and profit-and-loss statements to prove the figure. If you own a business, the court may also look at whether you are taking money out of the business in ways that lower your reported income.
Income that is temporary or one-time — like a bonus, inheritance, or lawsuit settlement — usually does not count toward ongoing support, though a judge can include it if the pattern is regular.
How time-share affects the payment amount
The formula reduces the payment based on how much time the child spends with each parent. This is measured in overnights per year. If one parent has the child 200 nights per year and the other has 165 nights, those numbers go into the formula as percentages (roughly 55 percent and 45 percent).
The more overnights the paying parent has, the lower the payment. If the parents split time equally (roughly 182 nights each), the formula produces a lower amount than if one parent has the child only on weekends. The logic is that when a parent spends more time with the child, they are already spending money on food, housing, and activities during those nights.
Time-share is based on the actual schedule, not what a custody order says. If the order says 50-50 but one parent regularly has the child extra nights, the court will count the actual nights. You will need a calendar or log showing overnights if the time-share is disputed.
If the child is an infant or very young and cannot stay overnight with one parent, the court may assign a lower time-share percentage to that parent even if they have daytime contact.
The formula step-by-step
The California formula works like this:
- Add both parents' gross income together to get combined parental income.
- Multiply that combined income by a base percentage (usually between 17 and 34 percent, depending on the number of children).
- Divide the result by the number of children to get the total support obligation.
- Multiply the total obligation by each parent's income percentage (their income divided by combined income) to see how much each parent owes.
- Adjust for time-share — the parent with more overnights pays less.
The base percentage increases with the number of children. For one child, it is typically 17 percent of combined income. For two children, 25 percent. For three, 29 percent. For four, 31 percent. For five or more, 35 percent. These percentages can shift slightly based on case law, so check the current state guidelines.
The result is the amount the higher-earning parent owes to the lower-earning parent each month. If both parents earn similar amounts, the formula may show that each owes the other, and the difference is paid by the higher earner.
Using the state worksheet to calculate yourself
California provides an official Child Support Guideline Worksheet (Form FL-192) that you can download from the court website or the Judicial Council of California website. The worksheet has blank lines for each parent's income, time-share percentages, and deductions (like health insurance premiums or existing child support orders). You fill it in and do the math.
The worksheet also includes sections for add-ons — costs that are calculated separately from the base formula. These include childcare costs (so one parent can work), health insurance premiums for the child, and uninsured medical expenses. These are split between parents based on their income percentages, not reduced by time-share.
If you use the worksheet, keep copies of the documents you used to fill it in: recent pay stubs, tax returns, proof of childcare costs, and insurance bills. If the other parent disputes your numbers, you will need to show where they came from.
Many county courts have local child support calculators on their websites. These are built on the formula and can give you a quick estimate, but they are not official court documents. The worksheet is the document that actually goes to court.
When the formula does not apply or can be changed
The formula applies to most cases, but California law allows a judge to order a different amount if the formula would be unjust or inappropriate. This is rare and requires a written finding by the judge explaining why. Common reasons include one parent having very high income (over $250,000 per year), unusual time-share arrangements, or special needs of the child.
If both parents agree in writing to a different amount, a judge can approve it without using the formula. This agreement must be in a signed document, usually part of a stipulation or settlement agreement. The judge will still review it to make sure it is not obviously unfair to the child.
If a parent's income changes significantly — a job loss, a major raise, or a change in time-share — either parent can ask the court to recalculate. The court will not automatically update the order; someone has to file a request.
What happens after you calculate the amount
Once you have a calculated amount, it becomes part of a court order. The order usually directs the paying parent to send the money to the Department of Child Support Services (DCSS), which collects it and sends it to the receiving parent. If the parents agree on a different arrangement, they can ask the court to approve it, but the court order still exists.
If the paying parent does not pay, the receiving parent can ask the court to enforce the order. The court can garnish wages, intercept tax refunds, suspend a driver's license, or hold the parent in contempt. The DCSS also has enforcement tools if the case is handled through the public child support program.
Child support continues until the child turns 18, or until age 19 if the child is still in high school full-time. If the child is disabled, support may continue longer. The order can be modified at any time if circumstances change significantly.
Frequently Asked Questions
What if one parent makes much more money than the other?
The formula still applies, but California has a high-income cap. If combined parental income exceeds a certain threshold (which changes yearly, currently around $250,000), the judge has discretion to apply the formula only to the capped amount or to consider other factors. The judge must write a finding explaining the decision.
Does the formula include child tax credits or refunds?
No. Tax credits and refunds are not part of gross income for the formula. However, the court can order the parents to split tax benefits related to the child, such as the child tax credit, as a separate issue from child support.
What if one parent is not working?
The court can assign imputed income — an estimated earning capacity — if the parent is deliberately avoiding work to lower support. The court looks at the parent's age, education, work history, and local job market. If a parent is legitimately unable to work (disability, caring for a young child), the court may assign a lower figure or none at all.
Can we agree to pay less than the formula says?
Yes, if both parents sign a written agreement and a judge approves it. The judge will review it to make sure it is not unfair to the child. The court is more likely to approve a lower amount if the receiving parent is not on public assistance and both parents understand what they are agreeing to.
How often can the order be changed?
Either parent can ask for a recalculation if there is a significant change in income or time-share. What counts as "significant" varies, but generally a 10 percent or more change in income or a substantial shift in custody triggers the right to ask. The court will not automatically update the order — someone has to file a request.