Stock Option Tax Calculator

Estimate the tax cost of exercising ISOs, NSOs, or receiving RSUs.

Grant Information

Tax Profile

Using 2024 federal brackets, standard deduction, and flat state rate approximations. AMT uses 2024 exemption amounts. NIIT of 3.8% applied when applicable.

Purchase Cost
—
Strike × Shares
Spread
—
(FMV − Strike) × Shares
Ordinary Income
—
Total Cash Needed
—
Purchase + all estimated taxes
Tax Component Estimated Amount Effective Rate

Cost Breakdown

How stock option taxes work

ISOs: No ordinary income tax at exercise. However, the spread (FMV − strike) is a preference item for the Alternative Minimum Tax (AMT). If you hold for 1+ year from exercise and 2+ years from grant date, gain at sale is taxed at long-term capital gains rates.

NSOs: The spread at exercise is taxed as ordinary income (federal + state + payroll). Any additional gain above FMV at sale is taxed as capital gains.

RSUs: The full fair market value at vesting is taxed as ordinary income. There is no exercise cost. Subsequent gain or loss is capital gains/loss.

Estimates use 2026 federal and state tax brackets. These are illustrative approximations — actual tax liability depends on many factors not captured here including itemized deductions, AMT credits, and state-specific rules. Consult a qualified tax advisor for your specific situation.