Illinois RSU Tax Calculator

No. RSUs are taxed once as ordinary income when they vest, based on the share price at vest. Any change in the shares’ value after that is a separate capital gain or loss, taxed only when you sell — a second, distinct event on different dollars, not the same income taxed again.

22% is the IRS flat federal withholding rate for supplemental wages (including RSU vests) up to $1,000,000 of year-to-date supplemental pay — it is a withholding mechanic, not your tax rate. On a $150,000 salary with a $50,000 vest in Illinois, the vest actually adds $12,000 of federal tax against $11,000 withheld, a $1,000 shortfall due at filing.

At vest, not at grant. Shares × fair market value at vest is added to your W-2 wages that year, with federal, Social Security, Medicare, and (in most states) state income tax withheld then. A later sale is taxed separately as a capital gain or loss from that vest-date cost basis.

On a $150,000 salary with a $50,000 vest in Illinois (single filer), this calculator estimates about $12,000 in additional federal tax and about $2,475 in additional Illinois state tax from the vest, plus $2,864 in Social Security and Medicare. Enter your own numbers in the calculator above for your figures.

Estimates use 2026 federal tables and the latest published state brackets (2026 where a state has released them, 2025 otherwise) and model one vest taxed as supplemental wages, using single-filer state brackets with no state standard deduction or other state-specific adjustments. Not modeled: your employer's specific sell-to-cover rounding and timing, vest timing within the year (withholding depends on year-to-date wages), local or city taxes, tax credits, the Alternative Minimum Tax, and state income sourcing if you worked in a different state during the vesting period. The state figure above is always what the vest owes at filing, not your employer's state withholding, which this calculator does not model.