Estimate temporary spousal support using the Santa Clara guideline and long-term support under Family Code § 4320 — with the 2026 California tax-conformity change applied.
This educational estimate is not legal advice. Long-term support has no statewide formula — a judge decides after § 4320 analysis. Even Santa Clara temporary support is only a starting point and can be deviated from for cause.
California is unusual: it has two completely different rules for spousal support, applied at different stages of the divorce. Most calculators don't make this distinction clearly, and that confuses almost everyone going through the process. The temporary number you see while the case is pending is rarely what the long-term order looks like.
While the divorce is pending the court orders temporary support to maintain the status quo. There is no statewide statutory formula, but California's bench has settled on the Santa Clara County guideline as the most widely adopted local rule, and it is baked into the Dissomaster and Xspouse software used in nearly every California family court:
Temp = 40% × (payor net − child support) − 50% × payee net
If the result is zero or negative, the formula yields no support. Other counties (notably Alameda) use slightly different parameters but produce broadly similar numbers. Temporary support is sometimes called pendente lite ("pending the lawsuit") support.
Once the divorce is final, long-term (post-judgment) support is set under § 4320, which lists 14+ factors a judge must consider. There is no formula by statute — and a judge is forbidden from simply applying the temporary formula. The big factors:
| § 4320 Factor |
|---|
| Earning capacity of each spouse and the marketable skills of the supported spouse |
| Extent supported spouse contributed to payor's education, training, career or license |
| Ability of payor to pay (income, assets, standard of living) |
| Needs of each party based on the marital standard of living |
| Obligations and assets, including separate property |
| Duration of the marriage |
| Ability of supported spouse to work without unduly interfering with dependent children |
| Age and health of both parties |
| Documented evidence of domestic violence |
| Immediate and specific tax consequences to each party |
| Balance of hardships |
| Goal that supported party become self-supporting within a reasonable period |
| Criminal conviction of an abusive spouse |
| Any other factors the court determines are just and equitable |
Federal tax law changed in 2019 (TCJA): spousal support paid under any agreement executed after December 31, 2018 is not deductible by the payor and not taxable to the recipient. California did not conform — until now. Effective January 1, 2026, California finally conforms:
| Agreement executed | Federal treatment | California treatment |
|---|---|---|
| On or before Dec 31, 2018 | Deductible by payor / taxable to payee | Same |
| Jan 1, 2019 – Dec 31, 2025 | Not deductible / not taxable | Still deductible by payor / taxable to payee (CA only) |
| On or after Jan 1, 2026 | Not deductible / not taxable | Same — CA conforms |
California's so-called 10-year rule is widely misunderstood. It does NOT guarantee lifetime alimony. Under § 4336, a marriage of 10 years or more is a "marriage of long duration," meaning the court keeps continuing jurisdiction over support indefinitely. The judge can still modify, reduce, or terminate support at any time when circumstances change. For marriages under 10 years, support is typically ordered for a "reasonable period," roughly half the length of the marriage.
Net income for support is gross income minus federal and California income tax, FICA, mandatory California SDI, health insurance premiums, mandatory union dues and retirement contributions, and any child or spousal support actually paid from a prior relationship. This is similar to the net disposable income used for child support under FC § 4055. Voluntary deductions like extra 401(k) above an employer match are usually not subtracted.
Calculators that show a single "California alimony number" are usually applying the Santa Clara temporary formula — useful for the pendente lite phase but irrelevant to the long-term order. Tools that show only "ranges" are reflecting the § 4320 reality: a judge has discretion, the same facts produce different awards in different counties, and the negotiation between attorneys can easily move the figure by 30%+.