RSU tax gap calculator

Picnic Tax
Estimate · Tax year 2026

RSU tax gap calculator

Supplemental withholding is 22%. Your real bracket often isn’t.

Your vest

Fair market value on the vest date. If you sold at vest, this is also the sale price unless you type a different one below.

Federal supplemental withholding

Employers usually withhold a flat 22% of RSU wages. The 37% rate is mandatory on supplemental wages over $1 million from one employer in a year.

Filing status

Used only to pick a rough 2026 federal bracket, not to prepare a return.

W-2 wages plus other ordinary income, not counting this vest. Placeholder is $200,000 — change it.

A rough flat or typical marginal rate for this audience — not a full state return.

Sell-to-cover share count from your brokerage. That dollar amount often includes FICA, so it is not a pure income-tax number.

Correct RSU basis is usually the vest FMV. Brokers often report $0 on Form 1099-B.

Holding period

Sold at vest is short-term. Long-term is more than one year after vest.

What usually goes wrong

  • 1099-B basis reported as $0

    The vest value is already W-2 wages. If your broker reports cost basis as $0, a DIY filing can tax the same dollars twice. Adjust basis to vest FMV unless a CPA tells you otherwise.

  • 22% withheld, 32 / 35 / 37% owed

    Payroll is allowed to use a flat supplemental rate. It is not your marginal bracket. High W-2 income plus a vest is how people owe in April despite “taxes already taken out.”

  • You moved, or the company thinks you didn’t

    Vest-day residency, remote work, and “convenience of the employer” rules can split one vest across states. A California vest after a Texas move is a classic mismatch between withholding and the return.

How this estimate is built

Tax year 2026 federal ordinary brackets and standard deductions (IRS Rev. Proc. 2025-32). Filing status chooses the bracket table only. “True” federal tax on the vest is the extra tax from stacking this compensation on top of your other ordinary income after the standard deduction — not a full Form 1040.

  • State tax uses the single rough rate you see, for both typical withholding and estimated tax. Graduated state brackets, local taxes, credits, and part-year residency are not modeled unless you type a custom rate.
  • The gap is income tax only: estimated tax minus 22% or 37% federal supplemental withholding minus the same state rate. Social Security, Medicare, Additional Medicare, NIIT on wages, AMT, and estimated-tax penalties are omitted.
  • Capital gain is sale proceeds minus the basis you enter. Short-term is taxed as extra ordinary income; long-term uses the 2026 0/15/20% brackets, plus 3.8% NIIT if MAGI looks to exceed $200,000 (single) or $250,000 (joint).
  • This is an estimate, not tax advice, and not a filing.
Picnic Tax provides this calculator as a free educational estimate. It does not consider your full return, does not create a client relationship, and is not a substitute for a CPA. Numbers will differ from software, payroll, and your actual 1040.
Estimated tax gap

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