Can a California judge deviate from the guideline child support amount?

Yes, under Family Code §4057, courts can deviate in limited circumstances: deferred home sale, significant asset wealth, unjust application, or high-income cases where guideline exceeds children's needs. Deviation is rare and must be on the record.

How does time-share percentage affect California child support?

Time-share (H%) is critical in the CA formula CS = K[HN - (H%)(TN)]. When the higher earner has more custody time, H% increases and support decreases. This creates a financial incentive that courts account for when evaluating custody.

Are California bonuses and stock options included in child support income?

Yes. California includes all income: salary, bonuses, commissions, RSU vesting, stock options, rental income, and business income. Irregular income is typically averaged over recent years. Large bonuses may trigger a child support true-up.

What are California hardship deductions for child support?

California allows hardship deductions under Family Code §4071 for minimum basic living expenses for other children you support, catastrophic losses, and extraordinary expenses. These reduce net disposable income and potentially lower support, but require court approval.

California Child Support Calculator

Q: What software do California courts use to calculate child support?

California courts use DissoMaster and XSpouse software which implement the exact CA guideline formula. Our calculator uses the same formula for estimates. For court purposes, hire an attorney to run official calculations.

Estimate CA guideline child support using the official formula: CS = K[HN − (H%)(TN)]. Covers standard, high-income, and multiple-children scenarios.

All calculations are private — nothing leaves your browser

Parent 1 Monthly Gross Income

Before taxes and deductions

Parent 2 Monthly Gross Income

Before taxes and deductions

Number of Children

Higher Earner's Time with Children %

H% in CA formula

Parent 1 Monthly Deductions

Union dues, mandatory withholding

Parent 2 Monthly Deductions

Health Insurance Premium

Monthly premium for children

Retirement Contributions

401k, 403b (higher earner)

CA Guideline Child Support (Monthly)

$608/mo

Base CS (Formula)$483/mo

K Factor25%

Higher Earner Net$4,696/mo

Total Net Disposable$7,894/mo

CA guideline formula: CS = K[HN − (H%)(TN)]. This is an estimate — DissoMaster software is used by CA courts.

Advanced Calculator

Time-share percentage impact chart, high-income deviation scenarios, and year-by-year CA guideline projection.

+ Open Advanced Calculator

CA Guideline Inputs

Higher Earner Annual Income

Lower Earner Annual Income

Number of Children

Higher Earner Time-Share %

CA Guideline CS = K[HN − (H%)(TN)]

$2,250/mo

K factor0.25

HN (monthly)$12,500

TN (combined)$17,500

Annual Total$27,000

Higher Earner Time-Share % vs. Monthly Support

H% Time-Share	Monthly CS	Annual	vs. 0%
0%	$3,125/mo	$37,500	$0
10%	$2,688/mo	$32,250	−$438
20% ← you	$2,250/mo	$27,000	−$875
30%	$1,813/mo	$21,750	−$1,313
40%	$1,375/mo	$16,500	−$1,750
50%	$938/mo	$11,250	−$2,188
60%	$500/mo	$6,000	−$2,625
70%	$63/mo	$750	−$3,063
80%	$0/mo	$0	−$3,125
90%	$0/mo	$0	−$3,125

Professional Simulator

Full CA income breakdown (W-2, SE, RSUs, rental, stock options), CA state/SDI tax, add-ons, what-if scenarios, and 20-year lifetime projection.

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Higher Earner Income — Total: $182,000/yr

W-2 / Salary

Self-Employment

Bonuses / RSUs

Rental Income

Stock Options

401k / Retirement Contr.

Union Dues / Other Deductions

Lower Earner Income — Total: $55,000/yr

W-2 / Salary

Self-Employment

Bonuses

Custody & Add-Ons

Children

Higher Earner Time-Share %

Health Insurance (child)/mo

Work-Related Childcare/mo

Educational Costs/mo

CA Full Guideline Analysis

$3,088/mo

HE Net Disposable

Gross: $182,000/yr

Federal tax: −$33,023

CA state/SDI: −$18,746

SE tax: −$4,239

Retirement: −$6,000

NDI: $119,992/yr ($9,999/mo)

Support Breakdown

Base CS: $1,814/mo

Health ins.: +$255/mo

Childcare: +$874/mo

Education: +$146/mo

Total: $3,088/mo

HE Income Share72.8%

Annual Total$37,060

% of HE NDI30.9%

HE Time-Share20%

How California Child Support Works

California uses one of the most precise child support formulas in the country, codified in Family Code §4055. The formula, calculated by specialized software called DissoMaster or XSpouse, accounts for each parent's net disposable income, time-share percentage, and mandatory deductions.

The California Guideline Formula

The official formula is: CS = K[HN − (H%)(TN)]

CS = K × [HN − (H%) × TN]

CS = Monthly child support amount
K = Fraction of combined income allocated to child support
HN = Higher earner's net disposable income
H% = Higher earner's time-share percentage with the children
TN = Total net disposable income (both parents combined)

K Factor by Number of Children

The K factor represents the percentage of combined income presumed necessary for child support. It increases with each child:

1 child: K = 0.20 (20%)
2 children: K = 0.25 (25%)
3 children: K = 0.30 (30%)
4 children: K = 0.35 (35%)
5+ children: K = 0.36–0.37+

Net Disposable Income

California calculates net disposable income by deducting from gross income: federal and state income taxes, FICA (Social Security/Medicare), California SDI, mandatory union dues, health insurance premiums for the parent, and any court-ordered child support or spousal support for other relationships.

Worked Example

Parent 1 earns $8,000/mo gross. Parent 2 earns $5,000/mo gross. Two children. Parent 1 (higher earner) has 35% time-share.

Parent 1 Net Disposable (HN)~$5,340/mo

Parent 2 Net Disposable~$3,337/mo

Total Net (TN)~$8,677/mo

K Factor (2 children)0.25

CS = 0.25 × [5,340 − 0.35 × 8,677]~$575/mo

+ Health Insurance Add-on~$125/mo

Total Monthly Support~$700/mo

The higher earner pays because they have more income despite having 35% time with the children.

Frequently Asked Questions

What software do California courts use to calculate child support? ▼

California courts use specialized software programs called DissoMaster and XSpouse. These programs implement the exact guideline formula and account for all deductions, tax filing statuses, and other factors. Our calculator uses the same formula but is a simplified estimate. For official court purposes, you should use DissoMaster or hire an attorney to run the calculations.

Can a California judge deviate from the guideline amount? ▼

Yes, but only in limited circumstances. Under Family Code §4057, courts can deviate from guideline if: the sale of a family home is deferred, a parent has significant wealth from assets rather than income, application would be unjust in a particular case, or in high-income cases where guideline exceeds the children's actual needs. Deviation is rare and must be justified on the record.

How does time-share affect California child support? ▼

Time-share (H%) is a critical variable in the CA formula. When the higher earner has more time with the children, their H% increases, which reduces the support amount. This creates a mathematical relationship between custody and money that can sometimes lead parents to contest custody primarily for financial reasons. Courts are aware of this and evaluate the best interests of children independently.

Are bonuses and stock options included in California income? ▼

Yes. California includes virtually all sources of income: salary, bonuses, commissions, RSU vesting, stock options, rental income, business income, and even lottery winnings. Courts typically average irregular income over recent years. When one parent receives a large bonus or stock grant, the other parent can request modification or a child support "true-up" for that year.

What are hardship deductions in California? ▼

California allows "hardship deductions" under Family Code §4071 for: minimum basic living expenses of other children you're supporting, catastrophic losses, and other extraordinary expenses. These deductions reduce the net disposable income used in the formula, potentially lowering the support amount. Hardship deductions require court approval and documentation.