RSU Net After-Tax Calculator (Vest)
Calculate exactly how much of your RSU vest you keep after federal, state, and FICA taxes — and how many shares are withheld to cover the tax bill.
How RSU Taxation Works at Vesting
Restricted Stock Units (RSUs) are taxed as ordinary W-2 income on the date they vest. The taxable amount is the fair market value of the shares on the vest date multiplied by the number of shares vesting. This income is added to your wages and reported on Form W-2 in Box 1. Your employer withholds federal income tax at the supplemental rate (22% for most employees), Social Security, Medicare, and applicable state income taxes at the time of vest.
This means you owe taxes whether or not you sell the shares — the act of vesting itself is the taxable event. Shares are typically withheld (sell-to-cover or net settlement) to fund the tax payment. Source: IRS Publication 525, Taxable and Nontaxable Income. Last updated: May 2026.
Federal Withholding: 22% vs Your Actual Bracket
The IRS requires employers to withhold at a flat supplemental rate of 22% for RSU income below $1 million. However, if your marginal federal tax bracket is 32%, 35%, or 37%, you will owe more than was withheld. This creates a tax balance due in April. Many high earners make quarterly estimated tax payments (Form 1040-ES) to cover the gap and avoid underpayment penalties. If your total supplemental wages exceed $1 million in a year, the withholding rate jumps to 37%.
RSU Tax Summary by Income Level
| Gross Vest ($) | Federal (22%) | FICA (7.65%) | State (CA 13.3%) | Net (CA High Earner) |
|---|---|---|---|---|
| $50,000 | $11,000 | $3,825 | $6,650 | $28,525 (57%) |
| $100,000 | $22,000 | $7,650 | $13,300 | $57,050 (57%) |
| $200,000 | $44,000 | $15,300 | $26,600 | $114,100 (57%) |
Note: FICA phases out for Social Security once you exceed the annual wage base ($176,100 in 2026). If your salary already exceeds this, RSU income is only subject to Medicare tax (1.45%), dramatically reducing your FICA rate. Source: IRS Publication 15. Last updated: May 2026.
After Vesting: Capital Gains Clock Starts
Your cost basis in RSU shares is the fair market value on the vest date — the same figure reported as W-2 income. If you sell immediately, there is typically no capital gain (the sell price equals the basis). If you hold for 12+ months and then sell at a higher price, the appreciation is taxed at long-term capital gains rates (0%, 15%, or 20% depending on your income). Many financial advisors recommend diversifying promptly after vesting to avoid single-stock concentration risk.