Child support · CA
California child support calculator
California runs every case through one statewide equation, so your timeshare percentage moves the figure as much as your paycheck does.
Rules read on official California pages on · Checked by Radif Partners · How we calculate
- Model
- State formula
- Income counted
- Net income
- Shared parenting
- No fixed formula
- 1 child, $5,000 / $3,000
- $1,250
- a month, rules of September 1, 2024
California child support is set by an equation, not a table: CS = K[HN − (H%)(TN)], where HN is the higher earner’s net disposable income, TN is both parents’ net disposable income combined, H% is the share of time the higher earner has the children, and K is an income fraction scaled by that timeshare (Family Code § 4055, current version operative September 1, 2024 after SB 343). For a parent netting $6,000 a month, another parent netting $4,000, two children and a 20% timeshare for the higher earner, the guideline is $1,920 a month; with no overnights for the higher earner it climbs to $2,400, and at an even split it falls to $591. The result is multiplied by 1.6 for two children and 2 for three. Child care tied to work or school and uninsured health costs are added on top and shared by income, and an obligor earning less than full-time minimum wage, about $2,929 a month in 2026, may get a low-income reduction.
Guideline child support in California, per month
$1,250
$15,000 a year
| Total net disposable income (TN) | $8,000 |
| High earner’s time with the children (H%) | 0.0% |
| K factor | 0.25 |
| Formula amount, 1 child (× 1) | $1,250 |
Estimate under the California guideline as published, from the incomes you enter. Deviations, imputed income, other children and the judge's findings can change the order. How this is calculated.
Timeshare is a variable inside the equation
Most states compute support first and then trim it for parenting time once the paying parent passes an overnight threshold. California has no threshold. H%, the percentage of time the higher earner has primary physical responsibility, sits in two places at once: it scales K up (1 + H%, or 2 − H% past one half) and it subtracts H% of the family’s total net income from the higher earner’s net. Every extra night therefore changes the result, from the first one. With net incomes of $6,000 and $4,000 and two children, the formula gives:
| Higher earner’s overnights a year | H% | Guideline, a month |
|---|---|---|
| 0 | 0% | $2,400 |
| 73 | 20% | $1,920 |
| 110 | 30% | $1,555 |
| 146 | 40% | $1,120 |
| 183 | 50% | $591 |
The drop from $2,400 to $591 is why the timeshare figure is so often the contested one in a California support hearing. Courts look at the actual pattern of care, and the DCSS calculator asks for it as a percentage, not as a custody label. When a parent does not appear and nobody proves the schedule, § 4055(b)(6) sets H% at zero if the absent parent is the higher earner.
Net disposable income under § 4059
The two incomes in the equation are net figures, but not the net on a pay stub. Section 4059 deducts federal and state income taxes actually payable after the filing status, credits and deductions a parent is entitled to, which can differ sharply from withholding. FICA, mandatory union dues and retirement contributions, health premiums for the parent and the children, support actually paid for children of another relationship and approved hardship deductions also come off. A new spouse’s or partner’s income is left out except in cases of extreme hardship to a child (§ 4057.5). The official DCSS Guideline Calculator does this tax work for you from gross figures; our calculator expects you to enter the net already.
The K factor after SB 343
SB 343 rewrote the income bands of the K fraction for orders computed on or after September 1, 2024. Combined net income up to the first band adds a slowly rising slice to a base of 0.165; the middle band is flat at 0.250; above $15,000 a month the fraction becomes 0.12 plus $1,200 divided by combined income, so it keeps shrinking as income grows. There is no income cap. A parent netting $30,000 with an ex netting $5,000 and one child in the other home gets a fraction of about 0.154 and a guideline of $4,629 a month; past that point the court may deviate only on proof that the amount exceeds the child’s needs (§ 4057). The statute’s own check: at H% 20% and combined net $1,000, K rounds to 0.21.
Child care add-on: the split changed in 2024
Work- or school-related child care is a mandatory add-on (§ 4062). Since SB 343, the shares are not plain income ratios: for this step the payer’s net is reduced by the basic support paid, and the recipient’s raised by it (§ 4061(c)-(d)). In the two-child case at a 20% timeshare, basic support of $1,920 moves the payer’s share of a $1,000 monthly child care bill from 60% ($600) to 40.8% ($408). The calculator above applies this adjusted split when you enter a child care amount.
Low-income adjustment
An obligor whose net disposable income is below the monthly gross pay of a full-time minimum-wage job ($16.90 an hour in 2026, which we compute to $2,929.33 a month) is presumed entitled to a reduction. An obligor netting $2,400 who has the child 73 nights a year, facing a parent netting $3,000, owes $396 for one child before the adjustment; the court may take off up to $72. The presumption is rebuttable, and a separate rule lets the judge cut support that still exceeds half the obligor’s net income (§ 4057(b)(5)). With one child at the 20% timeshare instead of two, the first example drops to $1,200, the youngest child’s share under § 4055(b)(8).
The California guideline this calculator applies
| Rule | California |
|---|---|
| Model | Statewide uniform guideline formula CS = K[HN - (H%)(TN)] (Fam. Code § 4055, as amended by SB 343) |
| Income counted | Net disposable income: gross minus taxes actually payable, FICA, mandatory retirement, health premiums (Fam. Code § 4059). |
| Shared parenting | No overnight formula in the calculator (see the rule below) |
| In force since | September 1, 2024 |
Monthly support for one paying parent, the other parent without income
| Paying parent’s monthly income | 1 child | 2 children | 3 children | 4 children |
|---|---|---|---|---|
| $2,000 | $378 | $605 | $757 | $870 |
| $3,000 | $607 | $970 | $1,213 | $1,395 |
| $4,000 | $904 | $1,446 | $1,807 | $2,078 |
| $5,000 | $1,248 | $1,997 | $2,496 | $2,871 |
| $6,000 | $1,500 | $2,400 | $3,000 | $3,450 |
| $8,000 | $2,000 | $3,200 | $4,000 | $4,600 |
| $10,000 | $2,500 | $4,000 | $5,000 | $5,750 |
| $12,500 | $2,749 | $4,398 | $5,498 | $6,323 |
| $15,000 | $2,999 | $4,798 | $5,998 | $6,898 |
| $20,000 | $3,600 | $5,760 | $7,200 | $8,280 |
How the amount is set. CS = K[HN - (H%)(TN)] (Fam. Code § 4055(a)). HN = high earner's net monthly disposable income; TN = total net monthly disposable income of both parents; H% = approximate percentage of time the high earner has primary physical responsibility for the children (average across children if time-shares differ). K = (1 + H%) if H% <= 50%, or (2 - H%) if H% > 50%, times the income fraction from the table in § 4055(b)(3). The result is for one child; multiply by the children multiplier in § 4055(b)(4). A positive CS is paid by the higher earner to the lower earner; a negative CS means the lower earner pays the absolute value (§ 4055(b)(5)). If the obligor's net disposable income is below the monthly gross income of full-time minimum wage (Lab. Code § 1182.12, 40 h x 52 weeks / 12), the low-income adjustment may reduce CS by at most CS x (MW_monthly - obligor net) / MW_monthly (§ 4055(b)(7)). source
Income. Net monthly disposable income: annual gross income minus state and federal income taxes actually payable, FICA (or equivalent retirement/disability contributions), mandatory union dues and mandatory retirement contributions, health insurance premiums for the parent and children and state disability insurance, child or spousal support actually paid for others under court order, court-allowed job-related expenses, and hardship deductions (Fam. Code § 4059).
Parenting time. Parenting time is built into the formula through H%, the high earner's approximate percentage of physical responsibility time, which enters both K (1 + H% or 2 - H%) and the term (H%)(TN) (§ 4055(b)(1)(D), (b)(3)). There is no overnight threshold.
Child care and health care. Mandatory add-on: employment- or education-related childcare costs actually incurred (§ 4062(a)(1)), shared in proportion to the parents' net incomes as adjusted under § 4061(c)-(d), unless the court orders otherwise (§ 4061(a)). Health insurance premiums are deducted from income (§ 4059(d)); reasonable uninsured health care costs are a mandatory add-on (§ 4062(a)(2)) shared in proportion to adjusted net incomes (§ 4061). Since September 1, 2024, add-ons are split in proportion to net disposable incomes; for this allocation the payer's net income is reduced by the basic child support and spousal support is moved from payer to recipient (§ 4061(c)-(d)). Educational/special needs and visitation travel are discretionary add-ons (§ 4062(b)).
Low incomes. Rebuttable presumption of a low-income adjustment when the obligor's net disposable income is below full-time minimum wage monthly gross income (40 h x 52 weeks); maximum reduction = CS x (threshold - obligor net) / threshold (§ 4055(b)(7)). With the 2026 state minimum wage of $16.90/hour the threshold computes to $2,929.33 per month.
When support ends. The duty of support continues for an unmarried child who is 18, a full-time high school student and not self-supporting, until the child completes 12th grade or turns 19, whichever comes first (Fam. Code § 3901(a)). source
The state also runs its own official child support calculator; use it, or the court's worksheet, for a filing.
Worth knowing in California
- The current K-factor table and low-income adjustment were enacted by SB 343 (Stats. 2023, ch. 213) and became operative September 1, 2024 (§ 4055(d)). source
- Guideline support is presumed correct; deviations are limited to listed factors such as stipulation, extraordinarily high income exceeding the children's needs, or special circumstances (§ 4057). source
- The income of a parent's new spouse or nonmarital partner is not considered except in extraordinary cases of extreme and severe hardship to a child (§ 4057.5). source
- Federal and state taxes are those actually payable after filing status, exclusions, deductions and credits, not current withholding (§ 4059(a)). source
- The California Department of Child Support Services publishes the statewide Guideline Calculator; its user guide was last updated July 21, 2026. source