RSU Tax Calculator United States

What the RSU tax calculator does

The calculator estimates what you owe when your restricted stock units vest and what happens if you later sell the shares. It shows the ordinary income the vest creates, the federal and payroll tax withheld, the value you keep, and the capital gain between the vest date and a sale.

Enter the number of shares vesting, the fair market value per share on the vest date, and your expected sale price if you plan to sell. If you want the flat-rate cap applied precisely, also enter any supplemental wages already paid this year. An RSU vest gives you shares and a tax bill at the same moment, so knowing the numbers in advance helps you avoid a shortfall at filing time and decide how many shares to sell to cover the tax.

How RSUs are taxed at vesting

When RSUs vest, the fair market value of the shares becomes ordinary compensation income: the number of shares multiplied by the share price on the vest date. It is reported on your W-2 with your salary and taxed the same way as wages.

The vest counts as supplemental wages, so employers usually withhold federal income tax at a flat supplemental rate instead of your personal marginal rate. The flat rate applies to the first portion of supplemental wages in the year, with a higher rate above a statutory cap. The vest is also subject to FICA, Social Security plus Medicare. The calculator applies the supplemental rate and FICA to the vest value. If you have several vests in a year, the cap applies to your combined supplemental wages, so entering the year-to-date figure matters for large grants.

Why the flat withholding rate can leave a gap

The flat supplemental rate is a default, not a measure of your actual tax. If your marginal federal bracket is higher than the flat rate, the tax withheld at vest may not cover what you owe, which is a common reason people with large RSU grants owe money when they file. If your overall rate is lower, too much may be withheld and you get it back as a refund. The calculator shows the effective withholding rate next to your vest value so you can judge whether to set aside more cash or adjust your estimated payments.

Your cost basis

The vest value is already taxed as income, so that value becomes the cost basis of your shares and is not taxed again when you sell. Only the change in price after the vest date counts for capital gains. A rise is a capital gain; a fall is a capital loss that may offset other gains. The calculator compares your sale price with the vest-date value, multiplied by the number of shares.

Short-term versus long-term gains

Selling within a year of vesting produces a short-term capital gain, taxed at ordinary income rates. Holding for more than a year makes the gain long-term, generally taxed at lower capital gains rates.

Some people sell at vest to diversify and keep things simple, with little or no gain to tax because the sale price is close to the vest price. Others hold for further appreciation and accept the risk that the price falls. The choice depends on how concentrated you are in one stock, your view of the company, and your broader financial plan.

Reading your result

The output separates the ordinary income created at vest, the federal and FICA amounts withheld, and the net value of the shares you keep. It also shows the effective withholding rate, to compare with your marginal bracket, and the capital gain at your entered sale price.

This estimates withholding, not a full tax return. State income tax, the additional Medicare tax on high earners and your other income all affect the final bill. Rerun it when a new batch vests or the share price moves, and confirm specifics with a tax professional before making decisions that depend on them.

This is general information only and not financial advice.

About This RSU Tax Calculator

Use this RSU tax calculator to get an instant, accurate estimate. The figures follow official IRS guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.