A Deeper Look at California Child Support Rules (2026)

Posted on Mar 31, 2026 by Griswold LaSalle Staff

A Deeper Look at California Child Support Rules (2026)

If you are dealing with child support in Fresno, Visalia, Tulare, Kings, or Hanford, understanding the current rules is essential. We’ll walk you through exactly how a judge determines the child support amount, factoring in the math and the new state laws for 2026. A recent law, Senate Bill (SB) 343, updated the calculation formulas to better reflect California’s high cost of living—the first change of this magnitude in about 30 years.

The Child Support Formula Explained (Made Simple)

California courts use a specific, required algebraic formula to calculate child support. This formula is “presumptively correct,” meaning a judge must use the guideline amount unless there are very limited, specific reasons to change it.

The goal of the formula is simple: to determine how much money both parents should set aside for the child’s needs.

The formal equation from Family Code section 4055 is: CS = K[HN – (H%)(TN)].

Here’s what those letters actually mean:

  • CS (Child Support): The final monthly support payment for one child.
  • TN (Total Net): The combined take-home pay (net income) of both parents.
  • HN (High Earner Net): The take-home pay of the parent who makes more money.
  • H% (Timeshare): The percentage of time the high-earning parent has the child in their physical care.
  • K (K-Factor); The set percentage of both parents’ combined income dedicated to the child.

Note: If you have more than one child, the base amount (CS) is adjusted. For example, it is multiplied by 1.6 for two children and 2.0 for three children. (Watch: Our 2026 Child Support Calculation Video walks you through this math step-by-step.)

New Rules for Income and Shared Costs ( SB 343 Updates)

What counts as income when calculating child support? The law broadly states that income from any source derived is considered. Due to the passing of SB 343, the court now explicitly confirms these payments as “income”.

  • Severance Pay: Money received after leaving a job.
  • Military Allowances: Basic Allowance for Housing (BAH) and Basic Allowance for Subsistence (BAS) are counted because they reduce personal living expenses, making more income available for child support.
  • Veterans’ Benefits: Most benefits that are not based on “need” must now be included.

Important Update on “Add-Ons”:

Mandatory costs like health care and child care (daycare) are no longer automatically split 50/50. These “add-on” costs may now be shared based on parents’ proportional income. For instance, if you earn 70% of the total family income, you may be ordered to pay 70% of the uninsured medical or daycare costs. (See how SB 343 impacts your specific income in our latest YouTube update.)

For basics on custody types and the biggest factors that impact your case, see our first guide: Understanding California Child Custody.

Modern Tools and Legal Protections

To ensure accuracy in child support cases across Tulare County and beyond, certified software programs are used. These tools are automatically updated every year to account for tax law changes and minimum wage increases, and they must be certified annually by the Judicial Council.

Get Professional Legal Help in Visalia, Fresno, and Hanford

Since the new math is more complex, even minor errors in calculating your “timeshare” (H%) or “mandatory deductions” can lead to you overpaying or underpaying thousands of dollars over time. Our family law team, led by Madison C. Erickson, serves clients across Fresno, Kings, and Tulare Counties. We use the latest certified software to ensure your support order is fair and accurate under the new 2026 guidelines.

Ready to move forward with your case in the Central Valley?