EMPLOYEE RESOURCE CENTER
Download AMT calculator
If you exercised any incentive stock options (ISOs) and did not sell them in the same year, you’ll need to calculate the alternative minimum tax (AMT) when it’s time to do your taxes. The spread between the price you paid for the options and what they’re worth when you exercise is counted as income when you calculate AMT.

AMT calculator
AMT calculator
Using the following information, Carta’s free AMT Calculator helps you estimate your potential tax bill:
- Your income
- Filing status
- Strike price
- Current fair market value (FMV) of your shares
- How many options you exercised (or you’re thinking of exercising)
After you have your AMT calculation, compare it to your ordinary income tax calculation. Whichever yields the higher amount is what you’ll owe to the IRS.
Calculating AMT can be complicated
Calculating AMT can be complicated and the taxes you owe might be prohibitively expensive. Estimating your AMT before you exercise and using a tax professional who specializes in equity can help you make more informed decisions.
DISCLOSURE: This communication is on behalf of eShares, Inc. dba Carta, Inc. ("Carta"). This communication is for informational purposes only, and contains general information only. Carta is not, by means of this communication, rendering accounting, business, financial, investment, legal, tax, or other professional advice or services. This publication is not a substitute for such professional advice or services nor should it be used as a basis for any decision or action that may affect your business or interests. Before making any decision or taking any action that may affect your business or interests, you should consult a qualified professional advisor. This communication is not intended as a recommendation, offer or solicitation for the purchase or sale of any security. Carta does not assume any liability for reliance on the information provided herein. © 2026 Carta. All rights reserved. Reproduction prohibited.