Is Child Support Based on Gross or Net Income in California?

Child support in California is based on net income, not gross. More precisely, the court starts with each parent’s gross income from almost any source, subtracts a fixed list of statutory deductions to arrive at net disposable income, and then runs those net figures through the statewide guideline formula. So the honest answer to whether child support is based on gross or net income in California is: gross income is where the math starts, but net disposable income is what the formula actually uses.

The distinction matters because the deductions are defined by statute. You do not get to subtract rent, car payments, or credit card bills. You do get to subtract taxes, mandatory retirement contributions, health premiums, and a handful of other specific items. Everything else in your budget is irrelevant to the calculation.

What Counts as Gross Income

California defines gross income broadly, sweeping in income from nearly any source.¹ A paycheck is only part of it. The court will typically count:

Wages, salaries, commissions, bonuses, and overtime
Dividends, interest, royalties, and trust distributions
Rental income from property you own
Social Security, workers’ compensation, unemployment, disability insurance, and veterans’ benefits not based on need
Pensions, annuities, and similar retirement payments
Severance pay, military housing and food allowances, and spousal support received from someone outside the current case

If you own a business, gross income means gross receipts minus the expenses required to run the business.¹ Courts can also count employer-provided benefits with real economic value, such as a company car or housing.

Two things stay out of gross income entirely: child support you receive for children from another relationship, and public assistance based on financial need.¹

The Deductions That Get You to Net Disposable Income

Once gross income is set, the court subtracts a defined list of items. Personal living expenses are not on the list; the deductions are set by statute.²

The allowed deductions are:

State and federal income taxes actually owed (not simply the amounts withheld), based on the parent’s real filing status and dependents
FICA contributions, or an equivalent amount for self-employed parents and those in alternative retirement systems
Mandatory retirement contributions and union dues required as a condition of employment
Health insurance premiums for the parent and for any children they are obligated to support, plus state disability insurance premiums
Child or spousal support the parent already pays under a court order for someone not involved in the current case
Job-related expenses the court finds necessary for the parent’s employment
Hardship deductions in defined circumstances

The mandatory-versus-voluntary line on retirement is where parents often get tripped up. If your employer requires you to contribute to a pension plan to keep your job, that contribution comes off. A voluntary 401(k) contribution does not, because nothing about the job forces you to make it.² The same logic applies to taxes: the deduction reflects what you actually owe given your real situation, not whatever your employer happens to withhold.

Hardship Deductions

Beyond the standard list, a parent can request an additional deduction for extreme financial hardship. The qualifying categories are narrow: extraordinary health expenses the parent is financially responsible for, uninsured losses from catastrophic events, and the minimum basic living costs of children from other relationships who live with the parent.³ The parent has to request it, and the court decides whether an adjustment is necessary.⁴

How Net Disposable Income Runs Through the Formula

Each parent’s net disposable income is what feeds California’s statewide guideline formula: CS = K[HN − (H%)(TN)].⁵ The pieces:

HN is the higher earner’s monthly net disposable income
TN is the two parents’ combined monthly net disposable income
H% is the approximate percentage of time the higher earner has primary physical responsibility for the children
K is a factor that shifts based on combined income and time share, representing the share of combined income allocated to support

For more than one child, the result is multiplied by a statutory factor: 1.6 for two children, 2.0 for three, and continuing up through ten.⁵ The state provides a free guideline calculator that runs the math for you once you enter each parent’s numbers.⁶

The takeaway for the gross-versus-net question: HN and TN are net figures. If someone tells you support was calculated on gross income, either they mean the raw starting point before the statutory deductions were applied, or the calculation was done wrong.

When the Court Uses Earning Capacity Instead of Actual Income

There is a significant exception to calculating support on actual income. If a parent appears to be intentionally unemployed or underemployed, the judge can assign an earning capacity and calculate support on that instead. Factors include the parent’s work and earnings history, skills, education, health, age, assets, criminal record, and the local job market.¹

A parent who walks away from a well-paid job or stops working without a documented reason can find support set against what they used to earn. A legitimate reason for the change, such as a documented disability or a layoff, generally keeps the court from imputing income.

One protection is written into the statute: a parent who is incarcerated or involuntarily institutionalized cannot be treated as voluntarily unemployed, regardless of the offense.¹ Support in that situation is calculated on what the parent actually earns, not on a pre-incarceration salary.

When Courts Deviate from the Guideline Amount

The guideline number is presumed correct, but the presumption can be rebutted. A judge can order a different amount if the guideline figure would be unjust or inappropriate in the case, and the court has to explain the departure in writing.⁷ Common grounds include extraordinarily high income by the paying parent, a child’s special needs, unequal contribution relative to custodial time, a deferred sale of the family home where its rental value exceeds carrying costs, a stipulation between the parents, or low-income hardship.

The Low-Income Adjustment

California has a built-in adjustment for low earners. If the paying parent’s monthly net disposable income is below the gross amount earned from working full time at minimum wage, a rebuttable presumption of a low-income adjustment applies.⁵ With California’s 2026 minimum wage at $16.90 per hour, that threshold works out to roughly $2,927 per month in gross minimum-wage income.⁸ Because the threshold moves with the wage floor, it updates automatically.⁹

The adjustment reduces support proportionally based on how far below the threshold the obligor’s income falls. Even after the adjustment, a court can deviate further if the result would still exceed 50 percent of the obligor’s net disposable income.⁷

A Note on Taxes

Because the calculation deducts taxes to reach net income, it is easy to assume the payments themselves carry tax consequences. They do not. Child support is not deductible for the parent who pays it and is not reportable as income for the parent who receives it, for both federal and California state taxes.¹⁰ The tax rules that historically applied to spousal support are different, so keep the two straight if you pay or receive both.

1
California Legislative Information. California Code FAM 4058 – Annual Gross Income
2
California Legislative Information. California Code FAM 4059 – Net Disposable Income
3
California Legislative Information. California Code FAM 4071 – Circumstances Evidencing Hardship
4
California Legislative Information. California Code FAM 4070 – Hardship Deductions
5
California Legislative Information. California Code FAM 4055 – Statewide Uniform Guideline for Determining Child Support Orders
6
California Child Support Services. Guideline Calculator
7
California Legislative Information. California Code FAM 4057 – Presumption of Correctness
8
California Department of Industrial Relations. Minimum Wage
9
California Department of Child Support Services. How Child Support Is Calculated Changes for the First Time in Decades
10
Internal Revenue Service. Alimony, Child Support, Court Awards, Damages