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Investing

Stock Option Calculator

Enter number of options, strike price, current stock price, and tax rate to see the intrinsic value and estimated after-tax value of your options.

Updated June 2026 · Editorial standards

Option Details

$
$
%
Intrinsic Value / Option
$25.00
Total Pre-Tax Value
$25,000
Estimated Tax
$9,250
After-Tax Value
$15,750

1,000 options at $50.00 strike vs $75.00 current price: intrinsic value $25.00/option = $25,000 pre-tax. After 37% tax: $15,750.Intrinsic value = current price minus strike price. Options are 'in the money' when current price exceeds strike. Remember: exercise triggers a taxable event. Consult a tax advisor before exercising large grants.

By the KalkWise Editorial Team Reviewed for accuracy Updated June 2026

What is the stock option calculator — intrinsic value & tax?

In short

A stock option's intrinsic value = current stock price − strike price. If you have 1,000 options with a $20 strike and the stock is at $35, intrinsic value is $15/option = $15,000 pre-tax. After a 37% tax rate, you keep ~$9,450.

Calculates intrinsic value per option, total pre-tax value, estimated tax cost, and after-tax value for employee stock options.

How to use this calculator

  1. 1Enter number of vested options.
  2. 2Enter strike price (grant price).
  3. 3Enter current stock price.
  4. 4Enter your marginal tax rate (federal + state for NSOs; LTCG rate for ISOs held long enough).

The formula

intrinsic=current price−strike price
after-tax=total pre-tax×(1−tax rate)
Intrinsic Value = max(0, S − K); Total Pre-Tax = Intrinsic × n; Tax = Total × t; After-Tax = Total − Tax
S
— Current stock price
K
— Strike price
n
— Number of options
t
— Tax rate

Worked example

The scenario

1,000 options, $20 strike, $35 current price, 37% tax rate.

gives

The result

Intrinsic value = $15/option. Pre-tax value = $15,000. Tax = $5,550. After-tax = $9,450.

Common use cases

  • Calculate the value of your equity compensation.
  • Decide whether to exercise options now or wait.
  • Compare job offers that include different equity packages.
  • Plan for the tax bill before exercising.

Limitations & assumptions

  • Calculates intrinsic value only — time value (extrinsic value) is excluded.
  • Tax treatment for ISOs vs. NSOs differs significantly.
  • Alternative Minimum Tax (AMT) may apply when exercising ISOs.
  • Does not account for lockup periods, blackout windows, or company-specific exercise rules.

Frequently asked questions

Non-qualified Stock Options (NSOs) are taxed as ordinary income at exercise. Incentive Stock Options (ISOs) may qualify for long-term capital gains treatment if you hold the shares for 1 year after exercise AND 2 years after grant. ISOs may trigger AMT.

Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.