California Bonus Tax Calculator (2025 & 2026)

California Bonus Tax Rates — 2025 vs. 2026 at a Glance

Yes, bonuses are taxed in California as supplemental wages. For separate bonus paychecks, California applies a flat Personal Income Tax (PIT) withholding rate of 10.23% — which also applies to stock options and RSUs. For commissions, overtime, and severance, the flat rate drops to 6.60%. Both state rates apply on top of the 22% federal supplemental rate and standard statutory payroll deductions.

Source: IRS IRC § 3402(g) and California EDD Publication DE 44. SDI unlimited wage base effective January 1, 2024.

How Much Will My Bonus Be After Taxes in California? (2026 Examples)

The table below shows exactly how much is withheld from four common bonus amounts in California for tax year 2026, using the Percentage Method on a separate bonus check. Calculations assume year-to-date wages have not exceeded the $184,500 Social Security cap and no pre-tax deferrals are applied.

2026 Percentage Method. Separate bonus check. Assumes YTD wages below $184,500 Social Security cap. No pre-tax 401(k) deferrals applied.

How California Taxes Bonuses and Supplemental Wages

California's Employment Development Department classifies bonuses, stock options, RSUs, commissions, overtime, and severance as supplemental wages — a legal distinction that determines which withholding method applies. Unlike regular wages, which run through progressive state tax tables, supplemental wages are subject to flat withholding rates at the time of payout. This is why bonus checks look dramatically different from a regular paycheck.

The most important distinction most payroll platforms miss: California applies two different flat PIT rates depending on the type of supplemental pay. Bonuses, stock options, and RSUs are withheld at 10.23%. Commissions, overtime, severance pay, and sick pay are withheld at 6.60%. This split comes directly from EDD Publication DE 44 and is non-negotiable — applying the wrong rate is a payroll compliance error.

Federal withholding follows a parallel structure. The IRS applies a flat 22% supplemental rate to bonus checks up to $1,000,000. Any portion above that threshold is withheld at 37%. These federal rates apply regardless of the employee's normal federal tax bracket — a single filer in the 12% bracket still has 22% withheld on their bonus at payout. The difference resolves at annual tax filing.

Since January 1, 2024, California eliminated the SDI wage cap entirely. The State Disability Insurance deduction now applies to every dollar of wages with no upper limit. For 2025, the SDI rate is 1.20%. For 2026, it rises to 1.30%. Executives receiving large RSU vests and high-value bonus packages are no longer protected by any cap — every dollar is subject to SDI withholding.

What Counts as a Supplemental Wage in California?

• Performance bonuses and year-end bonuses
• Sign-on bonuses and retention bonuses
• Restricted Stock Units (RSUs) upon vesting
• Stock option compensation
• Commission payments
• Draw-against-commission payouts
• Overtime pay processed separately
• Severance pay and separation packages
• Sick pay paid by a third party
• Back pay and retroactive wage adjustments
• Vacation pay paid out as a lump sum upon separation

Each category above may be subject to either the 10.23% or 6.60% California PIT rate depending on its classification under EDD DE 44 guidelines. When in doubt, commissions and performance-based draws are almost always 6.60% — not 10.23%. Running the wrong rate creates over-withholding that employees must claim back at filing, creating unnecessary friction for both payroll and staff.

Percentage Method vs. Aggregate Method: Which One Applies to Your Bonus?

Two methods govern how employers calculate withholding on supplemental wages — and the method used has a direct impact on how much comes out of your check. The Percentage Method produces a flat, predictable deduction. The Aggregate Method can temporarily push you into a far higher bracket and generate significant over-withholding that only corrects at year-end filing.

Most employers use the Percentage Method for separate bonus checks because it requires no reference to the employee's regular wage history or annual pay projections. The flat rate is applied, the check is issued, and the employee reconciles any difference at tax time. For employees in the 10% or 12% federal bracket, the 22% upfront withholding often means a refund in April.

The Aggregate Method creates more complexity. The employer annualizes the combined regular and supplemental pay for that period, looks up the withholding on the full hypothetical annual amount, subtracts what was already withheld on regular wages, and deducts the remainder from the bonus. Because a $10,000 bonus added to a $6,000 biweekly paycheck is briefly treated as if the employee earns $416,000 annually, the withholding jumps dramatically.

This calculator uses the Percentage Method — the method most commonly applied to separate supplemental paychecks. If your employer uses the Aggregate Method, the flat-rate estimate here still serves as a useful baseline. Your actual withholding may be higher depending on your regular pay, filing status, and withholding allowances on file.

Step-by-Step: How a $10,000 California Bonus Is Taxed in 2026

A $10,000 separate bonus check processed in California for tax year 2026 runs through five distinct withholding deductions before the net amount is deposited. The math below assumes year-to-date wages below the $184,500 Social Security cap, the bonus is classified as a performance bonus (not a commission), and no pre-tax deferrals are applied.

The $4,118.00 withheld is not a tax bill — it is an estimated tax prepayment. At year-end, your actual federal and California tax liability is calculated across your total annual income. If your combined income puts you in a lower effective bracket than the flat supplemental rates, the overpayment comes back as a refund.

What Happens When the Social Security Cap Is Reached?

Once year-to-date wages exceed $184,500 in 2026, the 6.2% Social Security deduction stops entirely. A $10,000 bonus received after the cap has been reached saves $620.00 in OASDI withholding — dropping total withholding from $4,118.00 to $3,498.00 and lifting net take-home from $5,882.00 to $6,502.00. High-earning employees who receive late-year bonuses often see noticeably larger net checks for exactly this reason.

Why Upfront Withholding Is Not Your Actual Tax Bill

The 41.18% withheld from a California bonus in 2026 consistently surprises employees — particularly those whose regular income sits in a lower federal bracket. Withholding at payout and tax liability at filing are two entirely separate calculations. The withholding is a mandatory government prepayment. The real number that matters is your effective tax rate across total annual income.

Federal tax brackets are marginal — each rate applies only to the slice of income within that bracket. A single filer earning $60,000 in regular wages and receiving a $10,000 bonus in 2026 has $2,200 withheld federally on the bonus. But the actual federal tax owed on that $10,000, calculated at filing within the correct marginal bracket, may be significantly less. The difference is refunded.

California's PIT works the same way. The flat 10.23% supplemental withholding rate is a conservative estimate that tends to over-withhold for employees below the top state brackets. California's top marginal rate of 13.3% applies only to income above $1,000,000 — so the flat 10.23% is not a worst-case scenario for most earners. It's a mid-range estimate designed to capture enough without requiring a precise bracket calculation at every payroll run.

FICA taxes — Social Security and Medicare — function differently. These are true fixed-rate obligations, not estimates. Social Security at 6.2% is a permanent deduction up to the annual wage cap. Medicare at 1.45% applies to every dollar with no limit. These amounts do not generate refunds and do not adjust based on annual income. What is withheld is what is owed.

Strategies to Reduce Tax Withholding on a California Bonus

Three legitimate strategies reduce the taxable portion of a bonus before withholding calculations run — each operates at the payroll processing stage, not after the fact.

1. Pre-Tax Traditional 401(k) Deferrals
   Directing a portion of the bonus into a traditional 401(k) reduces the taxable bonus amount for both federal and California state income tax purposes. For 2026, the standard employee pre-tax contribution limit is $23,500. Employees age 50 or older can contribute up to $31,000. Each dollar deferred reduces the taxable bonus dollar-for-dollar — a $5,000 deferral on a $10,000 bonus cuts the federal and California PIT calculations in half. FICA and SDI still apply to the gross amount.
2. Health Savings Account (HSA) Contributions
   HSA contributions made through payroll are pre-tax for federal income tax and FICA purposes. Employees enrolled in a qualifying high-deductible health plan can direct bonus funds toward their HSA up to the annual limit. For 2026, the individual coverage limit is $4,300 and the family coverage limit is $8,550. Unlike 401(k) deferrals, HSA contributions also reduce FICA withholding when processed through payroll — making them slightly more efficient per dollar deferred.
3. Adjusting Form W-4 and California Form DE 4
   If an employer uses the Aggregate Method and the combined withholding on the bonus paycheck appears excessive, submitting an updated Form W-4 with a higher number of allowances or an additional flat dollar reduction for the remainder of the year can offset the over-withholding before December 31. This avoids waiting until April to recover the difference. California Form DE 4 operates identically at the state level.

None of these strategies eliminate California's flat supplemental PIT rate or the SDI deduction — those are statutory and fixed. However, reducing the taxable bonus base through pre-tax deferrals delivers real, immediate take-home improvement on the largest portion of the withholding stack.

California Bonus Tax vs. Other States: How Does It Compare?

California carries one of the highest supplemental wage tax burdens in the country. The combination of a 10.23% flat PIT rate, unlimited SDI, and no income tax cap means a California bonus check is taxed more heavily than identical bonuses in most other states. The comparison below uses a $10,000 bonus under the Percentage Method for 2026 to illustrate the real difference across four states.

State estimates use the Percentage Method on a $10,000 separate bonus check, 2026 federal rates, YTD wages below Social Security cap, no pre-tax deferrals. Connecticut net varies by income — not calculable without full filing status data. Minnesota estimate excludes local taxes.

Florida's zero state income tax explains much of the salary negotiation behavior seen when California-based employees evaluate remote opportunities with Florida or Texas employers. On a $100,000 annual bonus, the difference between California's combined withholding and Florida's federal-only withholding is approximately $11,580 in additional California deductions — a real compensation gap that affects net take-home meaningfully at senior salary levels.

Are Bonuses Taxed at 22 or 40 Percent?

Both figures are correct — they just measure different things. The 22% federal supplemental rate is the single federal flat rate applied to the bonus. The ~40% figure represents the total combined stack: federal 22% + California PIT 10.23% + Social Security 6.2% + Medicare 1.45% + SDI 1.3% = 41.18%. Employees asking this question on Reddit or in payroll forums are typically reacting to the combined withholding, not realizing the 22% is only one of five deductions firing simultaneously.

Are Bonuses Taxed at 50% in California?

No. Under the Percentage Method, combined withholding in California for 2026 reaches approximately 41.18% for most employees — not 50%. The 50% figure sometimes circulates when employees receive large bonuses processed via the Aggregate Method, pushing their annualized income into California's higher state brackets temporarily. Even then, true 50%+ withholding requires very high income levels where the 37% federal rate and California's top rates converge. For the vast majority of bonus recipients, the actual withholding lands between 35% and 42% depending on OASDI cap status.

What California Employers Actually Pay on a Bonus Check

The employee withholding stack covers what comes out of the bonus check. Separately, the employer carries its own payroll tax obligations on every dollar of supplemental wages paid. These costs do not appear on the employee's pay stub — but they directly affect how companies budget total compensation and why bonus payroll runs cost more than the gross amount issued.

SUI, ETT, and FUTA apply only on the first $7,000 of wages per employee per year. If year-to-date wages already exceed $7,000 before the bonus is paid, employer unemployment tax liability on the bonus is $0. Employer share of Social Security (6.2%) and Medicare (1.45%) apply on the same base as employee deductions.

A new California employer paying a $10,000 year-end bonus to an employee whose total year-to-date wages are below $7,000 faces: SUI at 3.4% on up to $7,000 ($238 maximum), ETT at 0.1% ($7 maximum), and FUTA at the 2025 rate of 1.8% ($126 maximum). On top of this, the employer matches the employee's Social Security (6.2% of the bonus) and Medicare (1.45% of the bonus) — adding $745 in employer FICA on a $10,000 bonus. Total employer cost beyond the gross bonus can reach $1,116 in a worst-case new-employer, below-$7,000-YTD scenario.

For most mid-year bonuses paid to employees whose YTD wages already exceed $7,000, the SUI, ETT, and FUTA costs drop to $0 — only the employer FICA match remains. This makes the employer's true incremental cost of a bonus check after the $7,000 threshold just 7.65% above the gross amount: 6.2% Social Security match plus 1.45% Medicare match. Use the Employer Cost tab in the calculator above to model your specific payroll scenario.

Understanding California's FUTA Credit Reduction

California has carried an outstanding balance on its federal Title XII unemployment loan account for several years. When a state fails to repay these federal loans by November 10 of a given year, the IRS reduces the available FUTA tax credit for employers in that state. In 2025, California's credit reduction was 1.2%, raising the effective FUTA rate from the standard 0.6% to 1.8% on the first $7,000 of wages per employee — a maximum additional cost of $84 per employee compared to states with no credit reduction. Employers running bonus payrolls late in the calendar year should confirm California's current credit reduction status before making fourth-quarter FUTA deposits.

2025 vs. 2026: What Changed in California Payroll Tax?

Two payroll parameters shifted between 2025 and 2026 that directly affect bonus take-home estimates. The Social Security wage cap increased and the California SDI rate rose. Both changes are built into this calculator — selecting the correct tax year in the inputs ensures the right rates are applied automatically.

Source: IRS Revenue Procedure and Social Security Administration annual adjustments. California EDD Publication DE 44 (2025 and 2026 editions).

For a standard $10,000 bonus, the 2025-to-2026 SDI rate change adds $10.00 in additional withholding — a minor adjustment. The Social Security cap increase is more significant for employees earning between $176,100 and $184,500 annually, who now pay OASDI through a later point in the year before the cap is reached. High earners receiving large RSU vests or executive bonuses in Q1 are most likely to notice the extended OASDI window.

Which Tax Year Should I Select in the Calculator?

Select the tax year matching the date the bonus was or will be paid — not the year you are filing. A bonus deposited in January 2026 uses 2026 withholding rates regardless of when it was earned. A December 2025 bonus check uses 2025 rates. The payout date determines the applicable withholding schedule.

Self-Employed, Small Business, and Special Bonus Scenarios

W-2 employees are not the only group calculating California bonus tax. Small business owners, self-employed individuals, S-corporation officers, and LLC members each face distinct payroll structures when distributing supplemental compensation. The rules differ significantly from standard employee withholding.

S-Corporation Owner Bonuses

S-corporation officers who are also employees must receive reasonable compensation as W-2 wages — including any bonus distributions. These wages run through the same supplemental withholding stack as any other California employee: 22% federal, 10.23% California PIT, Social Security, Medicare, and SDI. The corporation pays the employer FICA match (6.2% Social Security + 1.45% Medicare). Distributions taken above reasonable W-2 compensation avoid FICA entirely — but the IRS actively scrutinizes S-corps that understate W-2 wages to reduce payroll tax obligations.

LLC Members and Self-Employed Bonus Equivalents

Single-member LLC owners and sole proprietors do not receive W-2 bonus checks — their income is reported on Schedule C and subject to self-employment tax rather than payroll withholding. The self-employment tax rate is 15.3% on net earnings up to the Social Security cap (covering both the employee and employer FICA shares), plus 2.9% Medicare above the cap. California taxes this income at regular PIT progressive rates — not the 10.23% supplemental flat rate. Self-employed Californians should use estimated quarterly payments to cover federal and state obligations rather than relying on bonus withholding mechanics.

Draw-Against-Commission Structures

Sales professionals who receive a base draw against future commissions operate in a gray area that creates frequent withholding errors. When the draw is paid, California employers should withhold at the 6.60% commission rate — not the 10.23% bonus rate. When commissions are reconciled against the draw and paid as a true-up, the same 6.60% applies. Employers who incorrectly apply 10.23% to commission-based draws create systematic over-withholding that sales employees can challenge by referencing EDD Publication DE 44's supplemental wage classification table.

Sign-On Bonuses and Clawback Provisions

Sign-on bonuses are taxed identically to performance bonuses — 10.23% California PIT plus the standard federal and FICA stack at payout. The complexity arises with repayment clauses. If an employee repays a sign-on bonus after leaving before the agreed tenure, the repaid amount does not automatically generate a payroll tax refund. The employee must file IRS Form 1040 and California Form 540 with a deduction or credit claim for the repaid amount under the claim-of-right doctrine. Payroll withholding on sign-on bonuses cannot be retroactively reversed through the payroll system.