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Updated for 2026 guidelines

California Child Support Calculator 2026

California has a strange problem in 2026: the state’s own official child support calculator is decertified and has been since December 13, 2025. This page explains why, runs the statutory formula on net incomes you supply, and is honest that no tool, including this one, is currently certified the way the official one used to be. This calculator is not certified for court use under California Rules of Court, rule 5.275.

Reviewed by SupportDecode Editorial Team Page content reviewed Sources Methodology Update log

Estimate California child support (Fam. Code 4055 formula)

Both parents' net monthly disposable income

Use the NET figure both sides agree on: pay after taxes and the other Fam. Code 4059 deductions. This tool asks for net on purpose. The tax conversion from gross pay is exactly the step the July 2025 federal tax law changed, and it is why the official state calculator is decertified right now. If this box ends up with the smaller number, the tool swaps the two incomes for you; the formula only cares which one is higher.

Same idea: that parent take-home figure after taxes and mandatory deductions.

Parenting time and children

H% in the formula: roughly how much of the time the parent who earns more has primary physical responsibility for the children. A typical alternate-weekend schedule is around 20, week-on week-off is 50. If it differs by child, average the percentages. This is the number custody time changes in California.

The section 4055(b)(4) multiplier table; this form covers 1 to 6 children.

Estimated monthly support (not court-certified): $599.00. This state's result is an estimate.

Estimate This state's result is an estimate.

The paying parent pays this amount to the receiving parent each month.

How this estimate was computed
Line itemAmount
Total net monthly disposable income of both parents (TN)Cal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$4,500.00
Fraction of income allocated for child support (TN band table)Section 4055(b)(3) five-band table as amended by SB 343Cal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$0.24
K factorK = (1 + H%) x fraction with H% = 0.2Cal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$0.29
CS = K[HN - (H%)(TN)] for one childCal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$599.17
CS is positive: the higher earner pays the lower earnerSection 4055(b)(5)Cal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$599.17
Guideline monthly child support (rounded to whole dollars)Statute does not prescribe rounding; certified calculators round to whole dollarsCal. Fam. Code 4055 (uniform guideline formula, K table, low-income adjustment; post-SB 343) (California Legislature (leginfo))$599.00

Assumptions

  • Incomes are stipulated net monthly disposable incomes; the Fam. Code sections 4058-4059 net-income computation (including post-H.R. 1 federal tax changes) is not performed.
  • The official DCSS Guideline Calculator was decertified by the Judicial Council on 2025-12-13 and remains decertified as of 2026-08-06; this estimate is not certified under CRC 5.275 and cannot be used in court.
  • The court or child support commissioner has final authority over the amount ordered; the guideline result is presumptively correct but rebuttable under Fam. Code section 4057.
  • Add-ons under Fam. Code section 4062 (childcare, uninsured health care, special needs, visitation travel) are not included in this base guideline amount.

Estimate only. The court or state agency calculation controls.

California guidelines, effective 2024-09-01.

Not certified for court use: California Rules of Court, rule 5.275 allows only Judicial Council-certified software in court, and this tool is not certified. The state's own DCSS Guideline Calculator has itself been decertified since December 13, 2025 because of the 2025 federal tax changes; the Judicial Council certification page tracks its status and lists the certified tools courts use meanwhile.

California guideline facts

Guideline model
Statewide algebraic formula: CS = K[HN − (H%)(TN)], Fam. Code § 4055source
Current formula version
SB 343 rewrite, operative September 1, 2024source
Official DCSS calculator
DECERTIFIED since December 13, 2025; still decertified at our August 6, 2026 checksource
Certified alternatives
Four commercial tools recertified by the Judicial Council through March 31, 2027source
Court-use certification rule
CRC 5.275: only Judicial Council-certified software may be used in courtsource
Low-income adjustment threshold
$2,929.33/month for 2026 (full-time state minimum wage of $16.90/hour, gross)source
Multi-child multipliers
1.6 for two children, 2.0 for three, 2.3 for four (table runs to ten)source
Parameter set effective
September 1, 2024 (SB 343 operative date)source
Next scheduled data review
January 1, 2027source

How the California formula works, in plain words

California is the only state in our coverage that writes its child support guideline as one line of algebra. Family Code section 4055 says CS = K times HN minus H% times TN. Strip the symbols away and it reads like this: take the higher earner’s net monthly income, subtract that parent’s time-adjusted share of the combined income, and multiply what is left by a percentage the statute calls K.

K is built from two ingredients. The first is a fraction of combined income the law sets aside for the children, from a five-band table rewritten by Senate Bill 343, operative September 1, 2024. At $4,500 of combined net income the fraction works out near 24 percent; in the flat middle band, $5,001 to $10,000, it is exactly 25 percent; at very high incomes it tapers. The second ingredient is parenting time. H% is the share of time the higher earner has primary responsibility for the children, and it scales K up or down. More time with the higher earner means less money moving between households, which is why timeshare is the custody lever in California in a way it is not in most states.

The whole formula produces the amount for one child. For more children, section 4055(b)(4) multiplies it: 1.6 for two, 2.0 for three, 2.3 for four, on up a published table to ten. And the sign of the result matters: if CS comes out negative, which can happen when the higher earner has the children most of the time, the lower earner pays the absolute value instead.

There is a safety valve for low-income parents. When the paying parent’s net income is below the monthly gross of a full-time minimum wage job, $2,929.33 in 2026 with the wage at $16.90 an hour, section 4055(b)(7) presumes a low-income adjustment. The court can reduce the order by up to the shortfall ratio; the presumption is rebuttable and the judge decides the actual cut.

Everything above runs on NET disposable income, which the code defines in sections 4058 and 4059 as gross income minus taxes and certain deductions. That tax step is where California is broken right now, and the next section tells that story.

Worked example: $3,000 and $1,500 net, 1 child, 20 percent timeshare

  1. Take a higher earner with $3,000 in stipulated net monthly disposable income and a lower earner with $1,500, one child, with the higher earner caring for the child 20 percent of the time. Remember these are net figures both sides agree on, not computed from gross pay.
  2. Combined net income, TN in the statute, is $3,000 plus $1,500, which is $4,500. That lands in the second table band, where the fraction is 0.131 plus 4,500 divided by 42,149, which is 0.237764.
  3. Because the higher earner’s timeshare of 20 percent is at or below 50 percent, K is 1 plus 0.20 times that fraction: 1.20 times 0.237764, which is 0.285317.
  4. The income the formula reaches is the higher earner’s $3,000 minus 20 percent of the $4,500 combined income, which is $3,000 minus $900, leaving $2,100.
  5. Child support is 0.285317 times $2,100, which is $599.17, and with one child the multiplier is 1.0. Rounded the way certified calculators round, the estimate is $599 a month, paid by the higher earner. A court running certified software with full tax inputs could land somewhere different; this is the statutory skeleton on agreed nets.

The steps above follow the calculation method described on our methodology page.

California guideline history, including the decertification

  1. California codified the statewide uniform guideline, the algebraic CS = K[HN − (H%)(TN)] formula, in what is now Family Code sections 4050 through 4076.source
  2. SB 343 became operative: a new five-band K table, the first formula revision in decades, plus a low-income adjustment tied to the full-time state minimum wage and proportional add-on allocation.source
  3. The federal budget bill H.R. 1 (P.L. 119-21) changed federal tax law mid-year, altering the net-income math every California support calculation depends on.source
  4. The Judicial Council decertified the official DCSS Guideline Calculator because it did not yet reflect the H.R. 1 tax changes; courts moved to alternate certified calculators.source
  5. The statewide minimum wage rose to $16.90 an hour, lifting the low-income adjustment threshold to $2,929.33 a month gross.source
  6. Our status check: the DCSS calculator row on the Judicial Council certification page still reads Decertified, while four commercial tools are recertified through March 31, 2027.source

California child support FAQs

Why is the official California child support calculator decertified?

Because federal tax law changed faster than the software. The July 4, 2025 federal budget bill, H.R. 1, rewrote tax rules mid-year. California support runs on net disposable income, which depends on those tax rules, so on December 13, 2025 the Judicial Council decertified the DCSS Guideline Calculator until its updates are complete. The public page still hosts the tool with a banner saying it does not yet reflect the tax changes. As of our August 6, 2026 review it had not been recertified.

What are courts using while the official calculator is down?

Certified commercial software. The Judicial Council certification page lists CalSupport, Family Law Software, FamilySoft SupportCalc, and Xspouse as recertified for 2026-27, with certifications running through March 31, 2027. DCSS has said child support offices and courts are using an alternate certified calculator during the update.

Can I use this calculator in my California court case?

No. California Rules of Court, rule 5.275 requires Judicial Council certification for any support software used in court, and certified software must compute net income under the statute and land within 1 percent of the correct amount by default. This tool is not certified and does not compute tax at all; it runs the formula on nets you supply. Use it to understand the math, then get the court-ready number from certified software or the family law facilitator.

What is H% and why does parenting time matter so much in California?

H% is the share of time the higher-earning parent has primary physical responsibility for the children. It sits inside the formula twice: it scales the K percentage and it subtracts time-adjusted income from the higher earner’s side. That makes timeshare a continuous dial rather than a threshold. In many states custody only changes support past a cliff, like 40 percent of overnights; in California every percentage point moves the number.

Can the lower-earning parent end up paying support?

Yes. Section 4055(b)(5) says a positive result is paid by the higher earner, but a negative result flips the direction: the lower earner pays the absolute value. That typically happens when the higher earner has the children well over half the time. This tool shows the direction on every result.

What is the low-income adjustment?

A rebuttable presumption in section 4055(b)(7). When the paying parent’s net disposable income is below the monthly gross of a full-time minimum wage job, $2,929.33 in 2026, the court presumes a reduction is warranted, up to the guideline amount times the income shortfall ratio. The statute compares net income to a gross benchmark; that reads oddly, but it is what the law says. The judge sets the actual reduction anywhere from zero to the maximum.

Why does this tool ask for net income instead of gross?

Honesty. The statute computes on net disposable income, and turning gross pay into net requires current federal tax math. That exact step is what H.R. 1 changed and what the state is still updating; it is why the official calculator is decertified. A tool that quietly applied old tax assumptions could be wrong in every result. Asking for stipulated nets keeps the part we compute, the section 4055 formula, verifiable.

When will the official calculator come back?

No date has been announced. The most recent DCSS announcement about the calculator is still the December 24, 2025 decertification notice, and the certification page showed the tool as decertified at our last check on August 6, 2026, with a March 2026 submission noted. We recheck the status on a quarterly cycle and will update this page when it changes.

Good to know in California

  • The guideline amount is presumptively correct under Fam. Code § 4057 but rebuttable, including for extraordinarily high earners, and courts have long-standing case law on both bonus income (percentage-of-bonus orders) and very high incomes. Pin cites are omitted here until verified against official reporters.
  • Income of a parent’s new spouse or partner generally cannot be considered under § 4057.5, outside an extreme-hardship exception.
  • Add-ons ride on top of the base figure: employment-related childcare and uninsured health costs are mandatory add-ons under § 4062, split in proportion to net incomes since SB 343.
  • In Title IV-D cases, rule 5.275(j) normally requires the DCSS calculator itself; with that tool decertified, offices and courts are working from alternate certified software, which is exactly why we link the certification status page below.

How to use this estimate

Enter net monthly disposable income for both parents, the figure left after taxes and the Family Code section 4059 deductions. We ask for net on purpose. Converting gross pay to net means applying current federal tax law, and that is precisely the computation the July 2025 tax bill upended and the reason the official calculator lost its certification. Rather than guess at tax math the state itself has not finished updating, this tool runs the statutory formula on nets you stipulate.

Do not worry about which income goes in which box. The formula cares only about which parent earns more, so if the entries come in reversed, the tool sorts them automatically.

The timeshare field is the percentage of time the higher-earning parent has primary responsibility for the children. Estimate it from the actual schedule; if it differs between children, average it. Small changes in this number move the result more than most people expect.

Then treat the output as a sketch, not a filing. Under rule 5.275, only Judicial Council-certified software can be used in court, this tool is not certified, and right now even the state’s own calculator is not either. For a number a court will accept, use one of the four certified commercial tools or ask the family law facilitator at your courthouse, both linked from the sources below.

What this estimate includes

  • The full Fam. Code § 4055 formula: the SB 343 five-band K table, the timeshare branch of K, and the sign rule for who pays
  • The § 4055(b)(4) multiplier for 1 to 6 children
  • The § 4055(b)(7) low-income adjustment check against the 2026 threshold of $2,929.33, with the maximum reduction shown
  • Automatic ordering of the two incomes, so a reversed entry never errors out

What it leaves out

  • The gross-to-net tax computation of §§ 4058-4059; you supply stipulated net figures because the post-H.R. 1 tax math is still in flux
  • Add-ons under § 4062: childcare, uninsured health costs, special needs, and visitation travel
  • Hardship deductions, new-spouse income questions under § 4057.5, and every § 4057 rebuttal a judge can weigh
  • Anything a certified calculator does with tax filing status, exemptions, or withholding details

Official sources

Official sources last verified: .

Reviewed by SupportDecode Editorial Team Page content reviewed Sources Methodology Update log

Changelog: page first published in estimate mode, with the SB 343 formula, the 2026 low-income threshold, and the DCSS calculator decertification status as of that date. We recheck the certification status quarterly; material changes are dated in the update log.