California child support at a glance
- Guideline model: Statewide formula, CS = K[HN − (H%)(TN)], using both parents' net disposable incomes and timeshare
- Income used: Each parent's net disposable monthly income and the time the child spends with each parent (Family Code §4055; California DCSS).
- Shared parenting time: There is no threshold: the percentage of time with the higher earner is a direct input to the formula (Family Code §4055).
- When support ends: At 18; support continues for an unmarried, full-time high school student who is not self-supporting until the child completes 12th grade or turns 19, whichever comes first (Family Code §3901).
Official calculator or worksheet: California guideline child support calculator
This page explains the rules; it does not calculate an order. Health insurance, child care, other children and deviations change the result. Use the official tool and confirm with a family-law attorney licensed in California.