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Stock Option Tax Calculator

Model your employee option tax — US ISO/NSO and UK EMI/Unapproved — across grant, exercise, and sale.

Free · no signup required · runs entirely in your browser

Educational only — not tax advice.

Stock option tax is jurisdiction-specific and fact-specific. This calculator models the common cases; your actual outcome depends on holding periods, state / regional rules, AMT carryforwards, and plan documentation. Work with a CPA / chartered accountant before exercising or selling.

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Spread at exercise$45,000
Tax at exercise$12,600

$0 federal income tax (ISO); AMT exposure on spread = 28% × 45,000 = 12,600

Tax at sale$39,000

Qualifying disposition — long-term capital gains on (sale − strike) × shares = 39,000

Total tax$51,600
Net proceeds after tax$143,400

Verdict

Qualifying ISO disposition

Maximum tax efficiency: 0 income tax at exercise (AMT only), and all gain at exit taxed as long-term capital gains. The path most ISO holders want.

Related resources

Related glossary terms