California Bonus Tax Calculator 2026 — How Much Will You Actually Take Home?

Quick answer: A $10,000 California bonus yields approximately $5,882 in take-home pay after federal (22%), California state (10.23%), Social Security (6.2%), Medicare (1.45%), and CA SDI (1.3%) — a combined ~41.18% effective withholding rate. This is withholding, not your final tax — your actual liability is determined when you file. Use the calculator below to see your exact breakdown.

Quick Look: Bonus Take-Home by Amount

See how much of your California bonus you'll take home at different bonus levels. These numbers assume Single filing status, standard W-4, and Flat Method withholding.

Note: These figures assume Single filing status and that you have not yet reached the Social Security wage base ($184,500 for 2026). CA SDI rate is 1.3% per the 2026 EDD rate schedule. Your actual take-home may differ based on your specific withholding situation.

Your Bonus Tax Breakdown: See Where Every Dollar Goes

A $10,000 bonus in California doesn't mean $10,000 in your pocket. Here's exactly where that money goes.

The Complete Tax Stack on a $10,000 Bonus

That's $4,118 in taxes on a $10,000 bonus — you keep about $5,882. The total effective tax rate is just over 41%.

Why California Has an Extra Tax on Your Bonus

California taxes bonuses at a flat rate of 10.23% for cash bonuses and stock options (RSUs). That's separate from:

• Federal income tax (22% flat for bonuses under $1M)
• Social Security (6.2% up to $184,500)
• Medicare (1.45% on all wages)
• California SDI (1.3% on all wages)

Most bonus calculators stop at federal and state tax. They miss the full picture. When you add FICA and SDI, the total withholding jumps to over 41%.

The Tax That Most Calculators Miss: California SDI

California State Disability Insurance (SDI) is 1.3% of your bonus in 2026. There is no wage cap — every dollar of your bonus is subject to SDI tax.

On a $10,000 bonus, that's $130. On a $100,000 bonus, it's $1,300. Most calculators don't include this deduction, which means they overstate your take-home pay by over 1%.

SDI provides short-term disability benefits for California workers. You pay into it with every paycheck, including bonuses. The 2026 rate of 1.3% is set by the California EDD and applies with no wage cap.

Social Security Wage Base: When You Stop Paying

Social Security tax (6.2%) has a wage base limit of $184,500 in 2026. Once your year-to-date earnings hit this amount, you stop paying Social Security tax on additional income.

If your base salary plus your bonus exceeds $184,500, you may not pay Social Security tax on your entire bonus. This means your effective tax rate drops.

Example: If you've already earned $184,500 in 2026, a $10,000 bonus won't be taxed at 6.2% for Social Security. Your take-home increases by $620.

The calculator on this page factors in your year-to-date earnings to show you the exact impact of the Social Security wage base.

Why Your Bonus Check is Smaller Than You Expected

If your bonus check looks smaller than expected, you're not alone. The "sticker shock" happens because bonuses are taxed differently than regular pay.

The 41% Rule of Thumb

For California workers, a good rule of thumb is that your bonus is taxed at approximately 41% total:

• 22% federal income tax
• 10.23% California state tax
• 6.2% Social Security
• 1.45% Medicare
• 1.3% California SDI

Total: ~41.18% effective tax rate

This means a $10,000 bonus yields approximately $5,882 in take-home pay. A $25,000 bonus yields about $14,704.

Why Bonuses Are Taxed at a Flat Rate

The IRS requires employers to withhold taxes on bonuses at a flat rate of 22% (or 37% over $1M). This is different from your regular paycheck, which is taxed based on your W-4 allowances and tax bracket.

Your regular paycheck uses a progressive tax system. A bonus uses a fixed percentage.

Here's the critical distinction: the 22% federal withholding is NOT your final tax liability. It's a prepayment.

• If your actual marginal tax rate is below 22%, you over-withheld and may get a refund
• If your actual marginal tax rate is above 22%, you under-withheld and may owe at filing

The same logic applies to California's 10.23% flat rate.

The "Surprise" Factor: Why 41% Feels Like So Much

When you see 41% of your bonus disappear, it feels like a lot. Consider this context:

• Regular paycheck withholding in California is often 25-35% depending on income
• Bonus withholding is higher because it's aggregated with your regular income for tax purposes
• Your employer uses a fixed rate rather than your specific W-4 allowances

The result is that most Californians see between 39-42% withheld from their bonuses, depending on their exact situation.

Common Bonus Withholding Misconceptions

Misconception 1: "My employer is taking too much tax."
The withholding is based on IRS and FTB rules. Your employer is following regulations, not making a mistake.

Misconception 2: "I'm being taxed at a higher rate than my regular pay."
The flat rate is the same for everyone. You're not being singled out.

Misconception 3: "I won't get any of this back."
If you over-withhold, you'll get a refund when you file your taxes. The 22% is a prepayment, not a final tax.

What to Do If Your Bonus Check Shocks You

1. Use this calculator to see exactly what should have been withheld
2. Check your actual tax bracket — if you're in the 12% bracket, you'll likely get a refund
3. Consider the aggregate method — ask your employer if they can combine your bonus with your regular paycheck for more accurate withholding
4. Adjust your W-4 — if you consistently over-withhold, you can adjust your allowances
5. Plan your budget — assume approximately 41% withholding for future bonus planning

The calculator below shows you exactly what you should take home. If your actual check differs significantly, talk to your payroll department.

Flat Method vs. Aggregate Method: Which is Better for You?

Your employer has two ways to withhold taxes from your bonus: the Flat (Percentage) Method and the Aggregate Method. The difference can be hundreds of dollars in take-home pay.

What is the Flat (Percentage) Method?

The Flat Method is the default for most employers. When you receive a bonus on a separate check, your employer applies fixed withholding rates:

• Federal: 22% for bonuses under $1M (37% on the excess over $1M)
• California: 10.23% for cash bonuses and stock options

Your regular salary, filing status, and W-4 allowances do not affect the withholding. It's a fixed percentage applied to the entire bonus.

When employers use it: Almost always for bonuses paid on a separate check. It's simple and predictable.

Who it's best for: Employees in the 22% federal tax bracket and the 10.23% California bracket — the withholding closely matches their actual tax liability.

What is the Aggregate Method?

The Aggregate Method combines your bonus with your regular paycheck for that pay period. The total is then taxed based on your W-4 and DE-4 withholding allowances, just like your regular pay.

• Federal: Taxed at your regular withholding rate based on your W-4
• California: Taxed at your regular withholding rate based on your DE-4

When employers use it: When your bonus is paid on the same check as your regular wages. Some employers offer it as an option.

Who it's best for: Employees whose actual tax bracket is significantly different from the flat rates — especially high earners or low earners.

Side-by-Side Comparison on a $10,000 Bonus

Here's how the two methods compare for a $10,000 bonus with a $75,000 base salary and Single filing status:

Key insight: The Aggregate Method is more accurate to your actual tax situation. If you're in a lower tax bracket, it withholds less and you keep more now. If you're in a higher bracket, it withholds more and you keep less now — but you avoid a surprise tax bill at filing.

Which Method Should You Choose?

Choose the Flat Method if:

• You're in the 22% federal tax bracket
• You want predictable, simple withholding
• Your bonus is paid as a separate check

Choose the Aggregate Method if:

• Your employer offers it as an option
• You're in a lower tax bracket (12% or below) — you'll get more cash now
• You're in a higher tax bracket (24%+) — you'll avoid owing at filing
• Your bonus is paid on the same check as regular pay

The bottom line: The Aggregate Method is usually more accurate to your specific tax situation. But most employers don't offer it as an option — they default to the Flat Method for simplicity.

Can You Ask Your Employer to Use the Aggregate Method?

Yes, but it's up to your employer. The IRS allows either method. Some payroll systems can handle both. Larger employers are more likely to offer the Aggregate Method.

Here's what to do:

1. Ask your payroll department if they can use the Aggregate Method for your bonus
2. Understand that if your bonus is paid with your regular check, Aggregate is likely already being used
3. If your bonus is paid separately, ask if they can combine it with your next paycheck for withholding purposes

What if they say no? The Flat Method is compliant with IRS and FTB rules. You'll still get the correct tax treatment when you file your return — if you over-withheld, you'll get a refund.

Will You Get a Tax Refund on Your Bonus?

The short answer is: it depends on your tax bracket. Here's exactly how to tell whether you'll get money back or owe more at tax filing.

Withholding vs. Actual Tax — The Critical Difference

Your bonus check shows how much your employer WITHHELD. This is a prepayment of your taxes.

Your ACTUAL TAX is what you owe based on your total annual income, deductions, and filing status.

The difference determines whether you get a refund or owe money:

• Withholding > Actual Tax → You get a refund
• Withholding < Actual Tax → You owe money at filing
• Withholding ≈ Actual Tax → You break even

When You'll Get a Refund

You're likely to get a refund if your marginal federal tax rate is BELOW 22% and your California marginal rate is BELOW 10.23%.

Example: You earn $45,000 per year (12% federal bracket) and get a $10,000 bonus. Your employer withholds 22% federal ($2,200) and 10.23% California ($1,023). But your actual federal tax on the bonus is only 12% ($1,200). You've over-withheld by $1,000 — expect a refund.

Typical refund scenarios (2026 brackets):

• Single filers earning under $50,400 taxable income (12% bracket)
• Married filers earning under $100,800 taxable income (12% bracket)
• Head of Household filers earning under $67,450 taxable income (12% bracket)

If you're in the 12% bracket, the 22% federal withholding is too high. You'll get the difference back when you file.

When You'll Owe More

You're likely to owe more if your marginal federal tax rate is ABOVE 22% and your California marginal rate is ABOVE 10.23%.

Example: You earn $200,000 per year (32% federal bracket) and get a $50,000 bonus. Your employer withholds 22% federal ($11,000). But your actual federal tax on the bonus is 32% ($16,000). You've under-withheld by $5,000 — expect to owe at filing.

Typical owe scenarios (2026 brackets):

• Single filers with taxable income over $105,700 (24%+ bracket)
• Married filers with taxable income over $211,400 (24%+ bracket)
• High-income earners subject to Additional Medicare Tax (0.9% over $200k/$250k)

How This Calculator Estimates Your Refund or Owe Amount

Based on your base salary, bonus amount, and filing status, this calculator estimates your marginal tax rate using 2026 federal brackets. It then compares your estimated actual tax to the withholding applied to your bonus.

The results panel shows:

• "You over-withheld by approximately $X — you may get a refund"
• "You under-withheld by approximately $X — you may owe at filing"
• "Withholding should be accurate" (if your bracket matches the flat rates)

This is an ESTIMATE. Your actual tax liability depends on your full financial picture — deductions, credits, other income, and more.

Should You Adjust Your W-4?

If you consistently:

• Get large refunds → You're over-withholding. Consider reducing your W-4 allowances or claiming exemption from withholding.
• Owe money → You're under-withholding. Consider increasing your W-4 allowances or making estimated tax payments.

For bonuses specifically:

• If you're in the 12% bracket, the flat 22% withholding is too high. Consider adjusting your W-4 to reduce withholding from your regular pay to offset the over-withholding.
• If you're in the 24%+ bracket, the flat 22% withholding is too low. Consider making estimated tax payments or increasing withholding from your regular pay.

Timing Matters: When Will You See Your Refund?

• Bonus withholding happens immediately when you receive your bonus
• Your refund or tax bill is determined when you file your tax return (typically by April 15)
• If you over-withheld, you'll get the excess back with your tax refund
• If you under-withheld, you'll need to pay the difference when you file

The Flat Method is designed to be a "safe harbor" — it may over-withhold for most people, which means you're more likely to get a refund than owe. This is intentional: the IRS and FTB want to avoid surprising taxpayers with a large tax bill.

How Your Salary Changes Your Bonus Tax

Your base salary determines your tax bracket. That bracket determines whether the 22% federal withholding is too high, too low, or just right.

Tax Bracket Basics for Bonus Withholding

Your base salary + bonus = your total taxable income. Your marginal tax bracket determines your actual tax rate on the bonus.

For California state tax, your actual California tax rate depends on your total income and filing status, but the 10.23% flat withholding rate works similarly.

$50,000 Salary + $10,000 Bonus vs. $150,000 Salary + $10,000 Bonus

Scenario A: $50,000 Salary + $10,000 Bonus

• Tax bracket: 12% federal
• Bonus withholding: 22% federal
• Result: You over-withheld by about 10 percentage points
• Estimated refund: ~$1,000 on the bonus

Scenario B: $150,000 Salary + $10,000 Bonus

• Tax bracket: 24% federal
• Bonus withholding: 22% federal
• Result: You under-withheld by about 2 percentage points
• Estimated owe: ~$200 on the bonus

Key takeaway: The same $10,000 bonus can mean different outcomes based on your salary. Higher earners owe more at filing. Lower earners get refunds.

FICA Impact: Social Security Wage Base

Social Security tax (6.2%) stops once you hit $184,500 in wages for the year. If your salary + bonus pushes you past this limit, your bonus may not be subject to Social Security tax.

Example: You earn $180,000 in salary and receive a $10,000 bonus.

• Your salary is $180,000 — $4,500 below the Social Security wage base
• Your bonus of $10,000 is taxed on the first $4,500 at 6.2% ($279)
• The remaining $5,500 is not subject to Social Security tax
• You save $341 compared to someone who hasn't hit the wage base

This calculator factors in the Social Security wage base when you provide your year-to-date earnings.

Additional Medicare Tax for High Earners

If your total wages exceed $200,000 (single) or $250,000 (joint), you pay an additional 0.9% Medicare tax on the excess. This applies to your bonus too.

Example: You earn $190,000 in salary and receive a $50,000 bonus.

• Total wages: $240,000
• Threshold: $200,000 (single)
• Excess: $40,000
• Additional Medicare Tax: $40,000 × 0.9% = $360

This is an employer obligation — they must withhold it when your year-to-date wages exceed the threshold. The calculator shows this as a separate line item.

How to Use Your Salary to Estimate Bonus Tax

1. Find your federal tax bracket — Use your annual income (salary + estimated bonus) to find your 2026 bracket.
2. Compare to 22% — If your bracket is above 22%, expect to owe more at filing. If below 22%, expect a refund.
3. Check your Social Security status — If your year-to-date earnings are near $184,500, you may save on Social Security tax.
4. Check Medicare thresholds — If your total income exceeds $200k/$250k, factor in Additional Medicare Tax.

The calculator does all of this automatically. Just enter your base salary, bonus, and filing status.

California Bonus Tax Rate 2026: What You Need to Know

Here are the specific 2026 tax rates that apply to California bonuses, with official source references.

2026 California Bonus Tax Rates

Source: California Franchise Tax Board (FTB) and California Employment Development Department (EDD) — DE 44 Employer's Guide Rev. 52 (2026)

Federal Bonus Tax Rates

Source: IRS Publication 15 (Circular E), IRS Publication 15-T

Why California Has Higher Supplemental Tax Rates Than Most States

California's 10.23% supplemental tax rate is one of the highest in the nation because California:

• Has no state income tax withholding cap — all wages are taxed
• Has a progressive state income tax system with a top rate of 13.3%
• Uses a flat supplemental rate to simplify withholding for employers
• Has its own state disability insurance (SDI) program funded through payroll taxes

Most states with income tax use a flat rate for supplemental wages (similar to California), but California's SDI adds 1.3% to the total in 2026.

2026 Rate Changes vs. 2025

The California SDI rate increased from 1.2% in 2025 to 1.3% in 2026, per the EDD's annual rate notice. The Social Security wage base also increased by $8,400, meaning more of your wages may be subject to Social Security tax in 2026 compared to 2025.

Official Sources for Rate Verification

All rates on this page are verified against official sources:

• IRS Publication 15 — Federal withholding rates
• IRS Publication 15-T— Federal withholding calculations
• IRS Rev. Proc. 2025-32 — 2026 federal tax brackets and standard deductions
• California FTB — State withholding rates
• California EDD DE 44 Rev. 52 (2026) — SDI rates and supplemental wage categories
• SSA Fact Sheet: 2026 Social Security Changes (Oct. 24, 2025) — Social Security wage base

This page was last updated in August 2026 with the most current rates available.

How Are Bonuses Taxed in California? (Step-by-Step)

Here's exactly how your bonus tax is calculated in California, step by step. Follow along with the numbers and see how your bonus is taxed.

Step 1: Start With Your Gross Bonus

Your employer determines your gross bonus amount. This is the base number before any deductions. For this example, we'll use a $10,000 cash bonus.

Step 2: Apply 401(k) or Other Pre-Tax Deductions

If you contribute to a 401(k), HSA, or other pre-tax plan, that amount is subtracted from your gross bonus before taxes are calculated.

Example: You contribute 10% of your bonus to a 401(k).

• 401(k) deferral: $10,000 × 10% = $1,000
• Taxable bonus: $10,000 - $1,000 = $9,000

Note: The calculator on this page includes a 401(k) contribution slider.

Step 3: Calculate Federal Income Tax (Flat 22%)

Federal tax is applied to the taxable bonus at 22% for bonuses under $1M.

Formula: Taxable Bonus × 22%
$9,000 × 22% = $1,980

Step 4: Calculate California State Tax (10.23%)

California taxes all supplemental wages at 10.23% — this rate applies to both cash bonuses and stock options/RSUs, per the California DE 44 Employer's Guide.

Formula: Taxable Bonus × 10.23%
$9,000 × 10.23% = $920.70

Step 5: Calculate Social Security (6.2%)

Social Security tax is 6.2% of your taxable bonus, up to the $184,500 wage base limit.

Formula: Taxable Bonus × 6.2% (if under wage base)
$9,000 × 6.2% = $558.00

Step 6: Calculate Medicare (1.45%)

Medicare tax is 1.45% of your taxable bonus. There is no wage cap.

Formula: Taxable Bonus × 1.45%
$9,000 × 1.45% = $130.50

Step 7: Calculate Additional Medicare Tax (0.9%)

If your total wages exceed $200,000 (single) or $250,000 (joint), you'll pay an additional 0.9% Medicare tax on the excess. This applies to your bonus.

For this example, assume no Additional Medicare Tax applies.

Step 8: Calculate California SDI (1.3%)

California SDI is 1.3% of your taxable bonus in 2026. There is no wage cap.

Formula: Taxable Bonus × 1.3%
$9,000 × 1.3% = $117.00

Step 9: Add Up All Taxes and Calculate Net

Total taxes on the taxable bonus:

• Federal: $1,980.00
• California: $920.70
• Social Security: $558.00
• Medicare: $130.50
• Additional Medicare: $0.00
• CA SDI: $117.00
• Total Tax: $3,706.20

Net bonus = Gross bonus - 401(k) deferral - Total taxes
$10,000 - $1,000 - $3,706.20 = $5,293.80

Without 401(k) deferral, the net would be $5,882.00 — the 401(k) contribution reduces take-home but provides tax-deferred retirement savings.

Complete Tax Stack for a $10,000 Bonus (No 401(k))

What If My Bonus Is Over $1 Million?

Federal tax changes on bonuses over $1 million:

• First $1M: 22% withholding
• Amount over $1M: 37% withholding

Example: $1.5M bonus in California

• First $1M at 22%: $220,000
• Next $500,000 at 37%: $185,000
• Total federal: $405,000
• California state (10.23%): $153,450
• FICA and SDI also apply

Net take-home on $1.5M bonus ≈ $870,000 — effective rate ~42%.

What If My Bonus Is RSU or Stock Options?

Per the California DE 44 Employer's Guide, RSUs and stock options are withheld at 10.23% — the same rate as cash bonuses. Both fall under the "bonuses and stock options" supplemental wage category.

Example: $10,000 RSU vesting in California

A $10,000 RSU vesting produces the same California withholding as a $10,000 cash bonus. Both are taxed at 10.23% under California's supplemental wage rules.

Why Understanding the Step-by-Step Matters

Knowing how your bonus is calculated helps you:

1. Verify your check — Compare your actual check to the step-by-step calculation
2. Plan your taxes — Know whether you'll owe or get a refund
3. Make decisions — Understand how different compensation types are withheld
4. Budget accurately — Know your actual take-home before you get the check
5. Communicate with payroll — Ask the right questions if something looks wrong

The calculator on this page follows every step above automatically. Just enter your numbers and see the complete breakdown.

Why This California Bonus Calculator Is Different

Most bonus calculators show one number and miss key taxes. This calculator includes every deduction — SDI, Additional Medicare, Social Security wage base — so your result matches your actual check.

Key Differences

• Includes CA SDI (1.3%): Most calculators skip this entirely. On a ,000 bonus, that's most tools miss.
• Flat vs. Aggregate comparison: See both methods side by side with dollar-amount differences based on your tax bracket.
• 401(k) impact slider: See exactly how pre-tax contributions reduce your withholding and affect take-home.
• Social Security wage base: Enter year-to-date earnings to see when you stop paying SS tax (,500 cap for 2026).
• Refund/owe estimation: Based on your salary and filing status, the calculator tells you whether you'll get a refund or owe at filing.
• RSU and stock option support: Per CA DE 44, both cash bonuses and stock options use 10.23% — this calculator handles both.

All rates are verified against IRS Publication 15, California FTB, EDD DE 44 Rev. 52, and SSA for the 2026 tax year.

Frequently Asked Questions About California Bonus Tax

Get answers to the most common questions about California bonus tax withholding, rates, and refunds.

How This Calculator Works — Methodology

This California bonus tax calculator uses the official 2026 withholding rates from the IRS, California Franchise Tax Board (FTB), and California EDD. Here's exactly how the math works.

Data Sources

• Federal withholding: IRS Publication 15 (Circular E), Supplemental Wage Withholding rates
• Federal tax brackets: IRS Revenue Procedure 2025-32 (Oct. 9, 2025)
• California withholding: California FTB and EDD DE 44 Employer's Guide Rev. 52 (2026)
• Social Security wage base: SSA Fact Sheet: 2026 Social Security Changes (Oct. 24, 2025) — $184,500
• Medicare rates: IRS, FICA Medicare rates and Additional Medicare Tax thresholds
• California SDI: California EDD, 2026 SDI rate (1.3%)

Calculation Logic

1. Gross bonus — The total bonus amount entered by the user
2. Pre-tax deductions — 401(k) or other pre-tax contributions reduce taxable income
3. Federal income tax — 22% flat rate for bonuses under $1M; 37% on amounts over $1M (Flat Method). For Aggregate Method, estimated at your salary-based marginal rate using 2026 brackets
4. California state tax — 10.23% for cash bonuses and stock options/RSUs (per DE 44 Rev. 52)
5. Social Security — 6.2% applied until year-to-date earnings reach $184,500
6. Medicare — 1.45% applied to all wages
7. Additional Medicare — 0.9% applied to wages above $200,000 (single) or $250,000 (joint)
8. California SDI — 1.3% applied to all wages with no wage cap (2026 EDD rate)
9. Net take-home — Gross bonus minus all taxes and pre-tax deductions

Withholding Method Logic

• Flat (Percentage) Method: Fixed rates (22% federal, 10.23% California) applied to the bonus
• Aggregate Method: Federal tax estimated at your marginal rate based on your salary and 2026 filing-status brackets; California at your regular withholding rate based on salary and DE-4

2026 Federal Bracket Thresholds Used (IRS Rev. Proc. 2025-32)

Assumptions

• All calculations are for the 2026 tax year
• California SDI rate is 1.3% for 2026 (EDD DE 44 Rev. 52)
• Social Security wage base is $184,500 for 2026
• Federal brackets are from IRS Rev. Proc. 2025-32
• Filing status and salary are used for aggregate method and refund estimates
• This is a withholding estimate — actual tax liability may vary

Limitations

• This calculator provides an estimate only — not tax advice
• Individual tax situations may vary based on deductions, credits, and other income
• Consult a tax professional for personalized advice
• Rates and limits are subject to change by the IRS and FTB

Last updated: August 2026

Related Calculators and Guides

Explore these related tools and articles to learn more about California taxes and bonus planning.

• California Bonus Tax Calculator (Alternative View)
• Texas Bonus Paycheck Calculator (No State Tax)
• New York Bonus Tax Calculator
• California CASDI / SDI Tax Calculator
• California Paycheck Calculator
• California DE-4 Withholding Calculator
• How to Calculate the 10.23% Supplemental Method
• California Employer Payroll Tax Calculator