RSU Tax Withholding Calculator 2026

Your RSUs vested. Is the 22% your employer withheld enough?

Enter your salary and the vest value. You get the tax the vest really adds at your 2026 federal brackets, the gap versus the flat 22% withheld, the Additional Medicare Tax, and the extra W-4 withholding per paycheck that closes it before the year ends.

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Your 2026 income

Salary and other W-2 wages, excluding the vest ($)

RSU income vesting this year, total ($)

Filing status

Other taxable income, optional ($)

Your own deduction instead of standard, optional ($)

Federal withholding rate on the vest, optional (%)

State tax rate on the vest, optional (%)

State withholding rate on the vest, optional (%)

Federal tax withheld from salary this year, optional ($)

Last year's total federal tax, optional ($)

Paychecks left this year, optional

Last year's AGI was over $150,000 (safe harbor is 110%)

Enter your salary and vest, then click Calculate.

What this does not cover

Tax year 2026 only. Brackets and deductions change every year.
Wages and ordinary income only. Tax on selling the shares (capital gain or loss against the vest-day basis), AMT, credits, itemised deductions you have not entered, the 3.8% net investment income tax and the Social Security wage base are not modelled.
State tax is a flat rate you enter. Graduated state brackets, local tax and multi-state sourcing can differ.
One total for the year. Vests are added together; the flat rate and the bracket math do not depend on when in the year each vest happens.
Salary withholding is assumed right unless you enter it, so the result isolates the vest.

Common questions

Why is tax withheld on my RSUs not enough?

Employers withhold federal income tax on a vest at a flat 22% supplemental rate (37% above $1,000,000). Your real tax is set by your bracket. If your income including the vest reaches the 24%, 32% or 35% bracket, 22% under-withholds and the difference is due when you file.

How much tax do I owe on RSUs?

The vest is ordinary wage income, so the tax it adds is the difference between your tax with and without it. Enter your salary and the vest value and the calculator returns that number, the withholding, and the gap.

Can I be over-withheld on RSUs?

Yes. If your total income lands in the 10% or 12% bracket, the flat 22% takes more than the vest adds. The difference returns as a refund.

How do I avoid an underpayment penalty on a big vest?

Withholding of at least 90% of this year's tax, or 100% of last year's (110% if last year's AGI was over $150,000), meets the safe harbor. Extra W-4 withholding late in the year counts as paid evenly through the year, which a late estimated payment does not.

What is the Additional Medicare Tax on RSUs?

A 0.9% tax on wages over $200,000 single or $250,000 joint (Form 8959). Employers begin withholding at $200,000 of wages regardless of filing status.

Is this tax advice?

No. It applies published 2026 IRS rules to the numbers you enter and ignores credits, AMT, capital gains on sale, state brackets and more. Confirm with a qualified tax professional.