Stock Option Exercise Calculator (ISO & NSO)
Estimate the tax when you exercise employee stock options in 2026 — NSOs taxed as wages (income tax + FICA) and ISOs with the alternative minimum tax (AMT), using 2026 AMT exemptions and the new 50% phase-out.
Estimates only — not tax advice. Tax rules change and depend on your situation; check with the tax authority or a tax professional.
How to use
- 1Choose ISO or NSO and enter shares, strike price and current fair market value.
- 2Enter your other taxable income and filing status.
- 3See the tax at exercise (and AMT for ISOs).
How it's calculated
Spread = shares × (FMV − strike). NSO: spread is wage income (income tax + FICA). ISO: no regular tax at exercise, but the spread is an AMT preference: AMT = 26%/28% × (AMTI − exemption), exemption reduced by 50% of AMTI above $500,000 ($1,000,000 joint); you pay the excess over regular tax.
Frequently asked questions
Do ISOs avoid tax?
Not at exercise if AMT applies — the spread counts for AMT. If you hold the shares 1 year after exercise and 2 years after grant, the gain is long-term when you sell.
What changed for AMT in 2026?
Exemption phase-out thresholds dropped to $500,000 ($1,000,000 joint) and the phase-out rate doubled to 50%, so large ISO exercises trigger AMT sooner.
Can I get AMT back?
Often yes — AMT paid on ISOs creates a credit you can use in later years when regular tax exceeds AMT.