Why do I owe extra tax on my RSUs at filing?

US employers typically withhold federal tax at the flat 22% supplemental rate, and often little or no state tax. If your marginal bracket is 32–37% and you live in a taxed state, that difference plus state tax and Medicare isn't fully withheld — so you owe it at filing. This tool shows the full gap up front.

Does this cover Canada?

Yes — pick a province and it uses your combined federal + provincial marginal rate (no Medicare), and currency switches to CAD.

Is my compensation data uploaded anywhere?

No. Everything stays in your browser on your device.

Calculators › Equity & Investing › RSU / Equity-Comp Tax Calculator › Hawaii

Calconomics

RSU / Equity-Comp Tax Calculator — Hawaii

Localized for Hawaii. Vested RSUs are taxed as ordinary income — but US employers usually withhold only 22% federal, so high earners get blindsided by a bill at filing. Enter your vest and location to see the real tax, the likely shortfall, and your true take-home, with US state and Canadian province rates built in.

Region

State / Province

Your vest

Shares vesting

Share price at vest

Your tax rates

Federal marginal rate your real top bracket

Employer withholding

Employer supplemental withholding US ~22%; CA ≈ marginal

Vest value (taxable income)

$50,000

Likely shortfall at filing

$11,225

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Net cash you keep

$27,775

Effective tax rate

44.45%

The numbers

Federal income tax	$16,000
State / Province income tax	$5,500
Medicare (US, 1.45%)	$725
Total tax	$22,225
Already withheld	$11,000

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Prices in

How it's calculated

Vest value = shares × price at vest, taxed as ordinary income.
US employers withhold federal at the flat 22% supplemental rate (37% over $1M); the shortfall is your full unpaid tax — federal above 22%, plus state and Medicare — due at filing.
Canada taxes vests at your combined federal + provincial marginal rate via the bonus method (≈ marginal).
Rates auto-fill by state/province as top-marginal estimates — edit your federal rate to match your bracket.

Our methodology & 2026 data sources →

Frequently asked questions

Why do I owe extra tax on my RSUs at filing?: US employers typically withhold federal tax at the flat 22% supplemental rate, and often little or no state tax. If your marginal bracket is 32–37% and you live in a taxed state, that difference plus state tax and Medicare isn't fully withheld — so you owe it at filing. This tool shows the full gap up front.
Does this cover Canada?: Yes — pick a province and it uses your combined federal + provincial marginal rate (no Medicare), and currency switches to CAD.
Is my compensation data uploaded anywhere?: No. Everything stays in your browser on your device.