ISO AMT Calculator

Free ISO AMT calculator: model the bargain element (spread) from incentive stock option exercise and tentative AMT vs regular tax—simplified educational model (Form 6251–style logic).

The ISO AMT Trap

Exercising ISOs with large spreads can trigger AMT on paper gains you can't yet realize. You may owe six-figure tax bills on illiquid shares (pre-IPO, lockup period, etc.).

ISO AMT calculator inputs and results

ISO Exercise Details

Enter your income and ISO exercise information

Your W-2 income and other taxable income (before ISO exercise)

(FMV at Exercise - Strike Price) × Number of Shares Exercised

Go deeper on the rules and planning ideas behind this calculator.