This tool uses the simplified Santa Clara guideline formula commonly cited in California temporary support discussions: 40% of the higher earner's net monthly income minus 50% of the lower earner's net monthly income, with an adjustment for child support paid. Real California courts use software like DissoMaster, XSpouse, or SupporTax, which include dozens of additional inputs. Numbers here are rough; treat them as orientation, not as the answer.
Estimated Temporary Support
—
Per month, based on the simplified Santa Clara guideline. Real numbers vary significantly by tax filing status, deductions, and county.
Long-Term Support — Duration Estimate
—
Based on the common rule of thumb that under-10-year marriages produce support for about half the length of the marriage. Long-term marriages (10+ years) keep the court's jurisdiction open indefinitely. The actual amount of long-term support is set by a judge weighing the 14 factors in Family Code §4320.
What this number is and is not
- Is: a rough estimate of temporary support — what one spouse may pay the other while a divorce is pending.
- Is not: the long-term support amount that will be in your judgment. That number is determined by a judge weighing the §4320 factors and is not formula-based.
- Is not: a DissoMaster output. DissoMaster runs full federal and California tax calculations on each spouse's actual situation.
- Is not: tax advice. For divorces finalized after 2018, federal law no longer makes spousal support deductible to the payer or taxable to the recipient — but California state taxes still treat it the old way.
How the estimate is calculated
The Santa Clara guideline, used in many California counties for temporary support, is:
temporary support = 0.40 × (higher net − child support paid)
− 0.50 × lower net
If the result is negative, no spousal support is paid. The formula assumes the higher earner is the payer; if the lower earner already pays child support, the calculation flips appropriately.
The duration estimate uses the common California rule of thumb: for marriages under 10 years, long-term spousal support typically runs about half the length of the marriage. For marriages of 10 years or more, the court retains jurisdiction indefinitely under Family Code §4336 — the amount and duration of support are then set by the judge weighing the §4320 factors.
What this tool does not capture
- Tax filing status (single, head of household) and how it affects net income.
- Other deductions: health insurance premiums, mandatory retirement, union dues.
- Other support obligations from previous relationships.
- The 14 §4320 factors that govern long-term support.
- County-specific guideline variations (Alameda, Marin, others use different formulas).
- Hardship deductions or extraordinary circumstances.
For a real case, an attorney or a paralegal with DissoMaster access can run an accurate calculation in about ten minutes. If the numbers here look meaningfully off from your situation, that is a good sign that you need a proper calculation done.