2026 CALIFORNIA BONUS TAX CALCULATOR
California Bonus Tax Calculator 2026
Estimate how much of your California bonus you keep after federal supplemental withholding, FICA, and California state taxes. Compare the IRS percentage method (22% federal, 37% above $1M cumulative supplemental wages) vs a pay-period aggregate estimate.
How California taxes your bonus paycheck
California applies a supplemental withholding rate on bonus payments in addition to the federal supplemental rates (22%, or 37% above $1 million cumulative). The combined withholding can make a bonus look heavily taxed, though your final liability depends on total annual income.
Example: $10,000 bonus on $$75,000 salary
Single filer, biweekly pay — percentage method (22% federal supplemental + state supplemental rate).
| Gross bonus | $10,000 |
| Federal tax withheld | -$2,200 |
| State tax withheld | -$1,023 |
| Social Security | -$620 |
| Medicare | -$145 |
| Net bonus (percentage method) | $6,012 |
Aggregate method net bonus on this example: $5,287 (bonus combined with regular wages for one pay period under ordinary percentage-method withholding — estimate only).
California bonus tax questions
How much of a $10,000 bonus do you keep in California?
On a $10,000 bonus in California, estimated take-home after taxes is about $6,012 under the flat-rate supplemental percentage method (22% federal under $1 million in cumulative supplemental wages; 37% above that threshold). This calculator also shows an aggregate estimate that combines the bonus with regular wages for one pay period (IRS Pub 15 percentage method). Figures assume standard 2026 withholding and single filing status.
What percentage of a bonus is taxed in California?
The estimated effective bonus tax rate on a $10,000 bonus in California is approximately 39.9% under the flat-rate supplemental percentage method shown in the example. Federal withholding is generally 22% (37% on cumulative supplemental wages over $1 million). California state withholding is estimated at $1,023. The aggregate card may show a different effective rate because it withholds on the combined pay-period paycheck using ordinary withholding tables.
How is a bonus taxed differently from regular pay in California?
Bonuses are supplemental wages. Employers may withhold federal income tax using the flat-rate supplemental method (22%, or 37% above $1 million in cumulative supplemental wages) or the aggregate method. This calculator shows both: the flat-rate percentage method and an aggregate estimate that adds the bonus to regular wages for the pay period, calculates withholding on the combined amount, and backs out regular-only withholding (IRS Pub 15). Your employer may use either IRS-allowed approach; withholding is only an upfront estimate — your final tax depends on total annual income when you file.
Does California have a separate bonus tax rate?
California publishes a separate supplemental / bonus withholding rate. Estimated California withholding on a $10,000 bonus is $1,023 using that flat supplemental rate in the percentage-method example.