California calculates child support using a specific formula based on both parents' income
California courts use the guideline formula to set child support amounts. The formula takes both parents' gross monthly income, subtracts certain deductions (like taxes and existing child support obligations), and applies a percentage based on how many children need support. The result is divided between the parents based on their income ratio and custody arrangement.
The formula itself is straightforward: each parent pays a percentage of their combined net income. For one child, that percentage is 20 percent. For two children, it is 25 percent. For three children, it is 30 percent, and so on. The court then splits this total between the parents based on how much each one earns relative to the other.
A judge can order a different amount if the guideline formula would be unjust or inappropriate in your specific situation — for example, if one parent has very high income, or if the custody arrangement is unusual. But the guideline amount is the starting point in nearly all cases.
Key Takeaways
- California uses a percentage-of-income formula that depends on both parents' gross income and the number of children, not on custody alone.
- The paying parent (obligor) sends money to the receiving parent (obligee), either directly or through the state's payment system.
- Child support continues until the child turns 18, or 19 if still in high school, unless a court order says otherwise.
- If either parent's income changes significantly, either parent can ask the court to modify the order.
- The state can enforce unpaid child support through wage garnishment, tax refund interception, and license suspension.
What counts as income for the child support calculation
Gross income includes wages, salary, commissions, bonuses, self-employment income, rental income, interest and dividends, and benefits like unemployment or disability. It does not include means-tested benefits like CalFresh (food stamps) or CalWORKs (cash information), and it does not include child support or spousal support the parent receives from someone else.
If you are self-employed, the court looks at your net business income — what you earn after legitimate business expenses. If you own a business with your spouse, the court will typically count your share of the business income. If you own a business with someone else, the court counts only your proportional share.
The court can also count income you are capable of earning if you are intentionally underemployed or unemployed. For example, if you quit a job to avoid paying child support, the court may calculate support based on what you were earning before, or what you could reasonably earn in your field. This is called imputed income.
How the court decides custody and its effect on support
Custody affects child support because it determines each parent's percentage of time with the child. California law recognizes two types of custody: legal custody (the right to make decisions about education, health care, and religion) and physical custody (where the child lives).
Physical custody can be sole (one parent has the child most of the time) or joint (both parents share time roughly equally). The more time the paying parent spends with the child, the lower their support obligation, because they are already spending money on the child's care during their time.
If one parent has the child 0 to 50 percent of the time, they are typically the paying parent. If both parents have roughly equal time (close to 50-50), the formula adjusts so that the higher-earning parent still pays, but the amount is reduced to account for the time the lower-earning parent spends with the child.
How payments are made and who collects the money
Child support can be paid directly from one parent to the other, but California strongly encourages using the state's Centralized Collection and Disbursement Unit (CCDU). When you pay through CCDU, the state records the payment, which protects both parents. The paying parent has proof they paid, and the receiving parent has an official record for their records.
If the court orders support, the paying parent's employer usually receives a wage withholding order. The employer deducts the support amount from the employee's paycheck and sends it to CCDU, which then forwards it to the receiving parent. This is the most common method because it is automatic and reliable.
If the paying parent is self-employed or does not have a regular employer, they can pay CCDU directly by check, electronic transfer, or credit card. Some parents arrange direct payment between themselves, but this only works if both agree and the receiving parent does not need the state to enforce the order.
When child support starts and stops
Child support begins on the date the court order is signed, unless the order specifies a different date. It does not go back to when the parents separated or when a case was filed — it starts from the order date forward. The only exception is if the parents have a written agreement that says otherwise.
Support continues until the child turns 18, or until they turn 19 if they are still enrolled in high school and living with a parent. If the child is disabled and cannot support themselves, either parent can ask the court to extend support beyond age 18 or 19. Support also stops if the child gets married, joins the military, or becomes emancipated by court order.
If the child turns 18 while still in high school, support continues through the end of that school year or until they turn 19, whichever comes first. Once the child graduates or turns 19, the obligation ends unless the court has ordered otherwise.
Modifying a child support order
Either parent can ask the court to change the support amount if there has been a material change in circumstances. This usually means a significant change in income — either parent lost a job, got a substantial raise, or had a major change in custody time.
A change in income of 10 percent or more is often considered material, but the court has discretion. You do not have to wait for a specific percentage change — you can ask for a modification if your circumstances have genuinely changed and the current order is no longer fair.
To request a modification, you file a request with the court that issued the original order, or with the local child support agency if they are enforcing the order. You will need to provide recent income documents (pay stubs, tax returns, or profit and loss statements) and explain what has changed. The other parent gets a chance to respond before the court decides.
Enforcement when child support is not paid
If the paying parent falls behind, California has several enforcement tools. The state can garnish wages — take money directly from the paycheck — up to 50 percent of disposable income if the parent is supporting another family, or up to 60 percent if not. The state can also intercept tax refunds, both state and federal, and explore them to the debt.
The state can suspend a driver's license, professional license, or recreational license if support is more than 30 days overdue. It can also report the debt to credit bureaus, which damages the paying parent's credit score. In cases of willful non-payment, the court can hold the parent in contempt and impose jail time.
The receiving parent can also ask the court to hold a hearing to enforce the order. At that hearing, the paying parent must explain why they have not paid. If they cannot show a good reason, the judge can order them to pay the back amount plus interest, attorney fees, and court costs.
Frequently Asked Questions
Does the parent with custody always receive child support?
No. The parent with less time with the child usually pays, but if both parents have nearly equal time, the higher-earning parent pays the lower-earning parent. The formula is based on income ratio and time-sharing, not custody alone.
Can child support be ordered if the parents were never married?
Yes. Either parent can ask the court to establish a child support order regardless of marital status. If paternity is in question, the court will address that first, usually through a DNA test or a signed acknowledgment of paternity.
What happens if the paying parent loses their job?
They should ask the court to modify the order as soon as possible. If they wait and fall behind, they can still ask for a modification, but they may owe back support. The court will not automatically reduce support just because income dropped — the parent must request it.
Can child support be waived or forgiven?
Parents can agree in writing to a different amount or to no support, but the court must approve any agreement. The court will not approve an agreement that leaves a child without adequate support, even if both parents consent.
Does remarriage affect child support?
A new spouse's income does not count toward child support. Only the parent's own income matters. However, if remarriage reduces the parent's actual expenses (for example, they no longer pay rent because they moved in with a spouse), the court may consider that when deciding whether to modify support.