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RunTheNumbers.us

RSU tax calculator

What one vest withholds against the tax it adds to your year, how much to set aside, and the tax when you sell.

Updated for the 2026 tax year · How we calculate this

Your numbers

The vest

$/ share

The grant · optional

$/ share

Your year

$
$
$/ yr

When you sell

This $48,000 vest at tax time

$4,800still to pay

Payroll withholds 22% federal, but this vest adds federal tax at about 32% of its value.

Set aside $4,800 from this vest.

Sell or keep that much cash for tax time, or pay it as an estimated tax payment.

ItemWithheldOwed
Federal income tax22% withheld, 32% owed$10,560$15,360
Social Security and Medicare$1,128$1,128
WA Cares and Paid Leave$278$278
Total$11,966$16,766

Of your 120 shares, about 30 are sold to cover the withholding, leaving 90 and $34 in cash. Each kept share’s cost basis is its $400 vest price. Brokers often report $0 or no basis on the 1099-B; use the vest price on Form 8949, or you pay tax on that income twice.

RSU plannerEvery vest this year, and the payments to cover themAdd your grants to see the whole year’s gap, estimated payment dates, pay by year and offers compared.Comp trackerEvery grant over the years, and what a promotion addsTrack what’s still to vest, your vest history at the real price and exchange rate, and pay by year with what-ifs.
Assumptions and limits2026 tax year · checked Oct 25, 2026

Figures used

Federal withholding on vests
22% (37% over $1,000,000)
Social Security wage base
$184,500
California / New York supplemental rate
10.23% / 11.7%
Long-term capital gains, single
0% to $49,450, 15% to $545,500, then 20%
Washington capital gains deduction
$278,000 (2025; 2026 not yet published)

Assumed

  • One employer, and no other income, deductions or credits.
  • Your salary is for the whole year.

Not modeled

  • Moving states between grant and vest.
  • Estimated payments or extra withholding you already make.
  • New York City and Yonkers income tax, and New York’s tax benefit recapture at high incomes.
  • Payroll programs in states other than California, Washington, New York and New Jersey.
  • Partial state exclusions for capital gains, and other gains or losses you have the same year.
  • Wash sales beyond a note when a sale is at a loss.

Sources

How we calculate thisReport a problem with this calculation