California RSU Tax Calculator
Estimate tax on RSU vesting in California. Federal 22% + California 10.23% + FICA. See sell-to-cover shares, net shares, and after-tax value.
California at a glance
RSU Tax Calculator 2026
Federal · State · FICA · Sell-to-cover
Salary, bonus, etc. — used for SS wage base, Medicare threshold, and bracket impact.
Net shares received after sell-to-cover
60.12
$9,018 after-tax value
Marginal bracket: 32%
Flat 22% supplemental wage withholding
6.2% on vest value
1.45% on all wages
CA supplemental withholding
AMT note: RSUs are taxed as ordinary income at vest and generally do not trigger Alternative Minimum Tax (AMT). AMT typically applies to incentive stock options (ISOs) when you exercise and hold. RSUs vest as compensation and are taxed like salary.
Employers typically withhold RSU vesting at 22% federal (37% on amounts over $1M) plus state supplemental rates and FICA. This calculator assumes the flat supplemental method. Actual withholding may vary if your employer uses the aggregate method.
RSU Tax in California
How California affects your vest, sell-to-cover, and net shares
RSU vesting tax in California
RSUs are taxed as ordinary income when they vest. The fair market value (FMV) on the vest date is added to your W-2 wages. Employers withhold at the supplemental rate: 22% federal (37% above $1M), 10.23% California state, and FICA (SS 6.2% up to $184,500, Medicare 1.45%).
With sell-to-cover, your employer sells a portion of the vesting shares to pay the tax and delivers the remaining shares to your brokerage. Shares sold = Tax withheld ÷ FMV.
California state tax on RSUs
California has state income tax. RSU vesting in California is subject to 10.23% supplemental withholding in addition to federal and FICA. Your net shares are lower than in no-tax states.
Compare with no-tax states
On a $15,000 vest, California state withholding alone = ~$1,535. In TX/FL/WA, state withholding = $0.
Compare RSU Tax by State
See how California compares to high-tax and no-tax states
All states use federal 22% + FICA — only state rate differs
View all states →The withholding, net shares, and after-tax value above come from the RSU count, share price, filing status, state, and other income you enter—not a third-party feed. At vest, RSUs are taxed as ordinary income at fair market value. We apply supplemental wage withholding (22% federal), FICA with the Social Security wage base, state supplemental rates, then estimate sell-to-cover shares. We also show marginal and effective tax rates based on your total income with and without the vest. Below are the formulas, the order we follow, and worked examples you can check by hand.
Formulas
| Line | Formula |
|---|---|
| Gross RSU income at vest | Number of RSUs × fair market value per share on vest date |
| Federal supplemental withholding | Gross RSU income × 22% (or split 22% / 37% above $1M) |
| Social Security | Lesser of (gross RSU income, remaining wage base) × 6.2% |
| Medicare | Gross RSU income × 1.45% |
| Additional Medicare | Portion of vest above $200,000 combined wages × 0.9% |
| State supplemental withholding | Gross RSU income × state supplemental rate |
| Total estimated withholding | Federal + Social Security + Medicare + Additional Medicare + state |
| Shares sold to cover taxes | Total estimated withholding ÷ fair market value per share |
| Net shares received | RSUs vesting − shares sold to cover |
| After-tax value | Net shares received × fair market value per share |
| Effective withholding rate | Total estimated withholding ÷ gross RSU income |
| Effective tax rate (annual estimate) | (Total tax with vest − total tax without vest) ÷ gross RSU income |
Order of operations
Calculate gross income at vest
Gross RSU income = RSUs × FMV per share
On the vest date, the full fair market value of vested shares is ordinary wage income—reported on your W-2, just like salary. This is separate from any capital gains when you later sell the shares.
Apply federal supplemental withholding
22% flat on gross RSU income (37% on amount over $1M)
Employers typically withhold RSU vesting using the same flat supplemental wage rate as bonuses. This is paycheck withholding, not your final tax bill.
Calculate FICA on the vest
6.2% Social Security (within wage base) + 1.45% Medicare + 0.9% Additional Medicare if over $200K
RSU vesting is subject to FICA like salary. If your other income already hit the Social Security wage base, no Social Security is withheld on the vest.
Apply state supplemental withholding
Gross RSU income × state supplemental rate
Each state sets its own supplemental withholding rate. High-tax states (CA, NY, NJ) withhold more, leaving fewer net shares after sell-to-cover.
Estimate sell-to-cover
Shares sold = total withholding ÷ FMV; net shares = RSUs − shares sold
Many employers automatically sell enough shares at vest to cover withholding and deposit the remainder in your brokerage. Fractional shares are common.
Compare withholding vs. estimated actual tax
Effective tax rate = incremental annual tax ÷ gross RSU income
We estimate your actual marginal and effective tax using federal and state brackets on total income with and without the vest. Withholding may be less than your true liability in high brackets—you may owe more at filing.
Worked example
100 RSUs × $150 FMV = $15,000 gross income, Single, $150,000 other annual income, California, 2026
100 × $150 = $15,000 ordinary income at vest
$3,300 federal (22%) + $930 Social Security + $217.50 Medicare + $1,534.50 California state = $5,982 total withholding (39.88%)
$5,982 ÷ $150 = 39.88 shares sold → 60.12 net shares worth $9,018
Estimated actual effective tax on the vest: 42.25% (Marginal bracket: 32%). Withholding (39.88%) may differ from what you owe when you file.
| Line item | Amount |
|---|---|
| RSUs vesting | 100 |
| Fair market value per share | $150 |
| Gross RSU income at vest | $15,000 |
| Federal supplemental withholding (22%) | $3,300 |
| Social Security (6.2%) | $930 |
| Medicare (1.45%) | $217.50 |
| Additional Medicare (0.9%) | $0 |
| State withholding | $1,534.50 |
| Total estimated withholding | $5,982 |
| Effective withholding rate | 39.88% |
| Shares sold to cover | 39.88 |
| Net shares received | 60.12 |
| After-tax value | $9,018 |
| Estimated effective tax rate | 42.25% |
| Marginal tax bracket | 32% |
California withholds 10.23% on supplemental wages. On a $15,000 vest, state withholding is $1,534.50.
With $200,000 in other income (above the $184,500 wage base), Social Security on a $15,000 vest is $0—only Medicare and federal withholding still apply.
A $1,500,000 vest ($1,500,000 gross): federal withholding is 22% on the first $1M ($220,000) + 37% on the excess ($185,000) = $405,000 before FICA.
2026 rates and limits we use
| Parameter | What we use |
|---|---|
| Federal supplemental rate (under $1M) | 22.0% |
| Federal supplemental rate (over $1M) | 37.0% |
| Social Security wage base (2026) | $184,500 |
| Social Security rate | 6.20% |
| Medicare rate | 1.45% |
| Additional Medicare rate | 0.90% |
| Additional Medicare withholding threshold | $200,000 |
| California supplemental rate (example) | 10.23% |
What we do not model on this page
We use flat-rate supplemental withholding only—not the aggregate method (combining vest with regular wages). We do not model local city taxes, capital gains on shares sold after vest, 83(b) elections, ISO/NSO/ESPP rules, broker 1099-B cost-basis adjustments, NIIT on future sales, or employer-specific withholding choices. Sell-to-cover assumes shares are sold at vest FMV with no trading costs. Your actual tax depends on total-year income, deductions, and credits when you file.
RSU Tax FAQ — California
Disclaimer: Estimates for planning purposes only. Not tax advice. Actual withholding and tax liability depend on your employer's payroll system, additional income, deductions, and filing. Consult a tax professional for guidance specific to your California situation.