If you’re looking for a replacement for DissoMaster, the Judicial Council of California has certified five guideline child support calculators, and Xspouse is the direct successor built by DissoMaster’s original developer. Thomson Reuters pulled DissoMaster from the market on March 31, 2025, but the statutory formula every certified program runs is unchanged, so the number you get out of the new software should match what DissoMaster would have produced from the same inputs.
The Five Certified Replacements
The Judicial Council certifies which programs courts and attorneys may use to calculate guideline support. As of April 2026, five calculators hold certification, all expiring March 31, 2027. Every certified program must produce results accurate to within one percent of the correct amount under the statutory formula.1Judicial Branch of California. California Rules of Court Rule 5.275 – Standards for Computer Software to Assist in Determining Support
- Xspouse. Built by the same developer behind DissoMaster and widely regarded as its direct replacement. It uses the same calculation engine.
- California Child Support Guideline Calculator (DCSS). A free tool from the Department of Child Support Services. It is the only calculator allowed in Title IV-D cases where a local child support agency is involved.
- Family Law Software. A comprehensive platform used primarily by attorneys and financial professionals.
- Cal Support and CalSupport Pro. Desktop-based calculators from Nolotech.
- FamilySoft SupportCalc. An attorney-oriented tool from LegalPlus.
Which one you use depends on the case. If a local child support agency is handling collection or enforcement, the DCSS calculator is mandatory. In private cases, the court, attorneys, and parties can use any of the five.2Judicial Branch of California. Guideline Support Calculators If your attorney or judge still says “DissoMaster,” that’s habit; the underlying program is now one of these five.
The Formula Every Certified Calculator Runs
All five programs implement the same algebraic formula from Family Code Section 4055: CS = K[HN − (H%)(TN)]. CS is the child support amount. K is the percentage of combined parental income allocated to child support. HN is the higher earner’s net monthly disposable income. H% is the percentage of time the higher earner has physical custody. TN is both parents’ combined net monthly disposable income.3California Legislative Information. California Family Code 4055
In plain terms, the formula figures out what share of total parental income should go toward the children, then adjusts that share based on how much time each parent spends with them. More custodial time for the higher earner means a lower cash payment, because that parent is already spending directly on the child during their time. The K factor itself varies with the number of children and each parent’s share of combined income.
Whatever number the software produces carries a rebuttable presumption of correctness. A court will adopt it unless someone presents evidence that the amount would be unjust or inappropriate.4California Legislative Information. California Family Code 4057 Most cases end at the guideline figure.
The Inputs That Actually Move the Number
The formula is short. The financial data feeding it is where the real work happens. Three inputs drive the result: each parent’s gross income, the deductions that reach net disposable income, and the timeshare split.
Gross Income
Gross income for support purposes means income from nearly every source: wages, bonuses, commissions, rents, dividends, pensions, Social Security benefits, unemployment and disability benefits, severance, trust income, and more.5California Legislative Information. California Family Code 4058 Child support received for children from a different relationship is excluded, and so is income from need-based public assistance. Spousal support received from someone outside the current case counts.
Attorneys typically gather at least two years of tax returns and three months of recent pay stubs. Pay stubs alone miss investment income, rental profits, and side business revenue that only appear on a return.
Deductions to Net Disposable Income
Software subtracts several categories of expense from gross income to get to net disposable income, which is what the formula actually uses. Key deductions include federal and state income taxes, Social Security and Medicare, mandatory union dues, health insurance premiums for the parent and any children the parent is legally obligated to support, necessary job-related expenses, and hardship deductions.1Judicial Branch of California. California Rules of Court Rule 5.275 – Standards for Computer Software to Assist in Determining Support Mortgage interest, property taxes, and charitable contributions reduce taxable income, which changes the tax calculation and ultimately the support figure.
Retirement contributions get special treatment. A mandatory pension required as a condition of employment is deductible. A voluntary 401(k) contribution generally is not, though courts have some discretion.
Timeshare
The H% variable swings the number dramatically. A parent with 20% custodial time will pay substantially more than a parent with 40%, holding everything else equal. Courts want the actual parenting plan, not estimates, so pin the schedule down before running any calculator.
Self-Employment, Imputed Income, and Variable Pay
For a self-employed parent, gross income is business receipts minus expenditures genuinely required to run the business.5California Legislative Information. California Family Code 4058 Courts routinely add back business deductions that look more like personal benefits: a company car used mainly for errands, a home office that includes the living room, meals expensed through the business. Depreciation on rental property is generally added back too, because it isn’t a real cash outflow. Owners of S-corporations and partnerships often show a modest salary while distributions flow through a K-1, and courts look at the full picture rather than the reported salary alone.
When a parent is voluntarily unemployed or deliberately underemployed, the court can impute income based on earning capacity rather than actual earnings, considering work history, skills, education, age, health, criminal record, and the local job market.5California Legislative Information. California Family Code 4058 A parent who quits a well-paying job right before a support hearing will almost certainly have that prior salary imputed. Incarceration cannot be treated as voluntary unemployment.
Bonuses, commissions, overtime, and stock grants create a problem for a fixed monthly order. California courts handle this with an Ostler-Smith order, named after a 1990 appellate case. The court sets base support using predictable salary, then adds a provision requiring the paying parent to turn over a percentage of any variable compensation when it actually arrives. The percentage typically mirrors what the guideline formula would produce for that income.
What the Software Can and Can’t Do for Spousal Support
Certified calculators produce temporary spousal support figures using county-specific formulas. The most common is the Santa Clara formula, which sets temporary support at roughly 40% of the higher earner’s net income minus 50% of the lower earner’s net income.6Judicial Branch of California. Temporary Spousal Support These formulas apply between filing and final judgment.
No calculator produces a permanent spousal support number. Once a divorce reaches final judgment, the court weighs the Family Code Section 4320 factors rather than plugging numbers into a formula. Those factors include each spouse’s earning capacity, contributions to the other spouse’s education or career, the marital standard of living, length of the marriage, age and health of both parties, any history of domestic violence, tax consequences, and whether the supported spouse can become self-supporting within a reasonable time.7California Legislative Information. California Family Code 4320 For marriages under ten years, courts generally expect self-sufficiency within half the length of the marriage. For marriages of ten years or longer, the court retains jurisdiction indefinitely.
For any divorce or separation agreement executed after 2018, spousal support is neither deductible by the payer nor taxable to the recipient.8Internal Revenue Service. Topic No. 452, Alimony and Separate Maintenance
Add-Ons and Deviations
The guideline formula produces a base number, not the full obligation. Family Code Section 4062 requires courts to order two categories of add-on:
- Childcare costs tied to a parent’s employment or education needed to become employable.
- Uninsured health care costs for the children, including medical, dental, and vision.
Courts have discretion to add:
- Educational or special needs costs such as private school tuition, tutoring, or therapy.
- Travel expenses for visitation when parents live far apart.
Add-ons are typically split in proportion to each parent’s net income, not 50/50.9California Legislative Information. California Family Code 4062
Deviations from the guideline are allowed but require a written explanation from the court stating the guideline amount, why the ordered amount differs, and why the deviation serves the children’s best interests.10California Legislative Information. California Family Code 405611Judicial Branch of California. California Rules of Court Rule 5.260 – General Provisions Regarding Support Cases12Judicial Council of California. Review of the Statewide Uniform Child Support Guideline 20254California Legislative Information. California Family Code 4057 a parent with significant custodial time who isn’t actually spending commensurately, and special circumstances such as unusual medical needs, differing time-share arrangements among siblings, or cases with more than two legal parents.
Modifying an Existing Order
A support order can change when circumstances change. Either parent can ask the court to modify, generally when the change would move the order by at least 20% or $50, whichever is less.13California Department of Child Support Services. Changing a Child Support Amount Common triggers are job loss, a significant raise, a changed parenting schedule, or a child aging out.
Modification requires filing a Request for Order. Filing fees range from $0 to $60 depending on the county, and fee waivers are available for low-income parents. The court reruns the guideline calculation with updated financial data using one of the certified programs, so both parties should expect to produce fresh income documentation. The modified order takes effect from the filing date of the request, not the hearing date, so a delay in getting on calendar doesn’t erase the financial change.