California Child Support Calculator (2026)
California calculates child support under guideline-formula guidelines (Cal. Fam. Code § 4055 (as amended by SB 343, eff. Sept. 1, 2024)). Estimate the guideline amount below.
California's guideline formula needs more than a dozen inputs (tax filing status, timeshare percentage, deductions) — a two-field shortcut would mislead you. The state's official calculator implements the full formula:
Open the official California calculator →Your Case Details
Answer a few questions to see your estimated range.
Approximate gap between higher-earner and lower-earner.
Estimated Monthly Support
$840 — $1,560
State formulas vary significantly. This estimate uses national averages — your state's guidelines may produce a different number.
Revisado Editorialmente — Contenido revisado en cuanto a exactitud utilizando investigación legal publicada, datos gubernamentales y registros judiciales verificados. Vea nuestra metodología
Reviewed by Leonard Goldberg, Editor · Last updated
California calculates child support with the statewide guideline formula CS = K[HN − (H%)(TN)] (Cal. Fam. Code § 4055 (as amended by SB 343, eff. Sept. 1, 2024)). The formula needs both parents' net incomes, the parenting-time split, and tax details — use the official state calculator linked above for your figure; this page explains what drives it.
How California Calculates Child Support
California uses a statewide algebraic guideline formula, CS = K[HN − (H%)(TN)]: K is a fraction set by combined-net-income bands and adjusted for parenting time, HN is the higher earner's net monthly disposable income, H% is the higher earner's share of parenting time, and TN is both parents' combined net monthly disposable income. Senate Bill 343 revised the K-bands and the low-income adjustment effective September 1, 2024 — the first major overhaul since 1992.
Statutory basis: Cal. Fam. Code § 4055 (as amended by SB 343, eff. Sept. 1, 2024). Exact figure: official California calculator.
Worked Example
Illustrative example under the current statutory formula: combined net income (TN) $8,000/month, higher earner (HN) $5,000, higher earner's timeshare (H%) 20%, one child. K in the $5,001–$10,000 band is 0.250; adjusted for timeshare K′ = 0.250 × (1 + 0.20) = 0.300. CS = 0.300 × [$5,000 − (0.20 × $8,000)] = 0.300 × $3,400 = $1,020/month guideline support. For two children the result is multiplied by 1.6, for three by 2.0 (§ 4055(b)(4)).
When Courts Deviate From the Guideline
- The parents stipulate to a different amount under Fam. Code § 4065
- Deferred sale of the family residence where its rental value exceeds the carrying costs (§ 4057(b)(2))
- The paying parent has an extraordinarily high income and the formula amount would exceed the children's needs (§ 4057(b)(3))
- A parent is not contributing to the children's needs commensurate with their custodial time (§ 4057(b)(4))
- Special circumstances — differing timeshare per child, equal timeshare with very disparate housing costs, children with special medical needs, or more than two legal parents (§ 4057(b)(5))
Frequently Asked Questions
Did California's child support formula change recently?
Yes — SB 343 amended Fam. Code § 4055 effective September 1, 2024: revised K-factor income bands, an expanded low-income adjustment tied to full-time minimum-wage earnings, and changed allocation of add-ons like childcare. Existing orders are not automatically modified; a parent must file for modification to get the new formula applied.
Is California child support based on gross or net income?
Net disposable monthly income — gross income minus mandatory deductions like taxes, mandatory union dues and retirement contributions, health premiums, and existing support obligations (Fam. Code § 4059).
What is the low-income adjustment?
If the paying parent's net disposable income is below what a full-time minimum-wage worker earns (roughly $2,929/month gross at the 2026 minimum wage), § 4055(b)(7) presumes a reduced support amount. The presumption is rebuttable.
Can parents agree to a different amount than the guideline?
Yes — under §§ 4057(b)(1) and 4065 parents may stipulate to a different amount if they acknowledge their rights, know the guideline amount is presumptively correct, and the court finds the agreement in the child's best interest.
Where can I calculate my California child support officially?
California Child Support Services runs the official Guideline Child Support Calculator at childsupport.ca.gov — the same § 4055 formula courts use. It remains an estimate; the final figure is set by a commissioner or judge.