How to Use the California Child Support Calculator – Quick Manual

Using California’s official child support calculator is fairly straightforward once you know what information it expects. This short manual walks you through the process so you can prepare everything ahead of time and understand what the calculator is doing behind the scenes. The instructions below are based on the official guideline calculator from the California Department of Child Support Services (DCSS) and the requirements in the California Family Code.

1. Start with the official calculator

For a full explanation of how California’s guideline formula works, see our main guide: California Child Support Calculator – Official 2025 Guide.

California has a state-approved child support calculator operated by the California Department of Child Support Services (DCSS):

• Official Calculator:
  
  California Guideline Child Support Calculator
  

If you want more detail while you work, DCSS also provides a short user guide (PDF) linked from the same page.

2. Gather a few key numbers before you begin

You do not need stacks of paperwork, but you should have a basic picture of the following items before you start entering numbers.

Parent income

The calculator asks for each parent’s monthly income. This can include wages, self-employment earnings, commissions, overtime, and other income categories listed in the California Family Code.

You do not need to convert everything into net income yourself. The official calculator helps apply taxes and standard deductions so it can estimate each parent’s net disposable income.

Parenting time (timeshare)

Next, think about how much time the child spends with each parent during a typical year. It does not have to be exact to the minute, but it should reflect the real schedule over time, such as about 50/50, 70/30, or 80/20.

This time share figure has a noticeable effect on the final guideline amount, so use the best realistic estimate you can.

Child-related expenses

Some costs can be added on top of the basic formula under California law. Common examples include:

• work-related childcare costs
• uninsured medical or dental expenses for the child
• travel expenses related to visitation when parents live far apart
• certain educational or special-needs costs

If any of these apply to your situation, have approximate monthly or annual figures ready so you can include them when the calculator asks.

3. Enter your information into the calculator

Once you have the main numbers, open the official California Guideline Child Support Calculator and start entering your information into the fields provided:

• income for each parent
• each parent’s percentage of parenting time
• childcare and other allowed expenses, if applicable

The calculator applies the statewide guideline formula automatically. You do not need to work with the formula yourself; the system uses the data you enter to compute an estimated guideline child support amount.

4. Review the result and what it means

After you click to calculate, the tool displays an estimated monthly support amount. This number reflects the statewide guideline in the California Family Code, which courts generally follow unless a judge makes written findings that a different amount is appropriate under the law.

It is important to keep in mind:

• the calculator shows an estimate based on the information you entered
• the legally binding amount comes from a court order or a local child support agency decision, not from the calculator itself

5. If you need help, free court-based assistance is available

If you are unsure about how to enter your information or how to read the result, California’s courts offer free help through Family Law Facilitator and Self-Help Centers:

Family Law Facilitator and Court-Based Self-Help Services

These offices can:

• explain how the guideline works in your type of case
• help you check your inputs in the calculator
• assist with child support forms and procedures

They do not act as your personal attorney, but they can make it much easier to understand the process and move your case forward.