Stock Option & RSU Value Estimator

After-tax value on an RSU grant

For 400 vesting RSU shares at a $48 fair market value, the gross value is $19,200. Note that for RSUs specifically, the strike price field doesn't apply -- RSUs have no exercise cost, unlike stock options. At a combined 32% tax rate on the spread, tax due is $6,144, leaving an after-tax value of $13,056.

For stock options instead of RSUs, the spread is fair market value minus strike price, not the full share value -- switching the grant-type field to options changes which formula runs, since options only have value above the strike price while RSUs are worth their full share value at vesting.

Vesting is what triggers the tax event for RSUs -- unlike options, you don't choose when to exercise; the shares become taxable income automatically at fair market value on the vest date.

What a flat 32% doesn't capture

Flat tax on spread. AMT, 83(b), and trading windows are not modeled. RSU income is typically taxed as ordinary income at your marginal rate plus payroll taxes, which frequently isn't a flat, evenly-distributed 32% -- large single-year vests can push you into a higher bracket for that portion of income.

Incentive stock options carry AMT (Alternative Minimum Tax) exposure that a flat-rate model like this one doesn't calculate -- exercising ISOs without planning around AMT is one of the most common expensive mistakes in equity compensation.

Employer stock plans (like an ESPP) have their own discount and holding-period rules that don't map onto this RSU/option framework -- see the Employee Stock Purchase Plan (ESPP) Calculator for that specific structure.

Related equity-compensation questions

If the actual tax withholding on your vest doesn't match what you expect to owe at tax time, the Restricted Stock Unit (RSU) Tax Calculator breaks withholding out from total tax liability.

For the vesting schedule itself -- how much vests and when, including cliffs -- see the Stock Options Vesting & Cliff Calculator.

Frequently Asked Questions (FAQ)