Calculator Inputs
Large screens use 3 columns, smaller screens 2 columns, and mobile uses 1 column.
Plotly Graph
The chart compares modeled sale prices against estimated net proceeds after exercise cost, taxes, dilution effects, and fees.
Formula Used
Time-based vested % = (completed vesting months / total vesting months) × 100
Effective vested % = smaller of manual vested % and time-based vested %
Exercised options = granted options × effective vested % × exercise %
Effective shares = exercised options × (1 − dilution %)
Exercise cost = exercised options × strike price
Current intrinsic value = max(current FMV − strike price, 0) × effective shares
Future gross value = future sale price × effective shares
Net proceeds = future gross value − exercise cost − estimated tax − fees
Breakeven share price = (exercise cost + estimated tax + fees) / effective shares
How to Use This Calculator
- Choose the option type: NSO or ISO.
- Enter your grant size and current vesting inputs.
- Set the strike price and current fair market value.
- Add a modeled future sale price for scenario planning.
- Enter ordinary tax, capital gains tax, and any AMT buffer.
- Include dilution and fees for a more realistic estimate.
- Click Calculate to show results above the form.
- Use the CSV and PDF buttons to export your results.
Example Data Table
| Scenario | Granted | Vested % | Strike | FMV | Sale Price | Net Proceeds |
|---|---|---|---|---|---|---|
| Conservative | 5,000 | 50% | $4.00 | $10.00 | $12.00 | $10,060.00 |
| Growth Case | 10,000 | 60% | $5.00 | $18.00 | $24.00 | $53,260.00 |
| Aggressive | 15,000 | 75% | $6.50 | $21.00 | $32.00 | $138,743.75 |
Frequently Asked Questions
1. What does this stock option calculator estimate?
It estimates vested options, exercised shares, exercise cost, intrinsic value, taxes, breakeven price, ROI, and projected net proceeds under different sale-price assumptions.
2. Why does the calculator ask for both vested percent and vesting months?
The page uses the smaller value. That keeps results conservative when a grant schedule and a manual estimate do not perfectly match.
3. How is dilution handled here?
Dilution reduces the effective shares used in value calculations. It is a simplified planning input, not a cap-table simulation.
4. What is the difference between ISO and NSO in this tool?
NSO mode applies ordinary tax to the spread at exercise and capital-gains tax to later appreciation. ISO mode shifts focus toward capital gains and optional AMT exposure.
5. Are the tax outputs exact?
No. They are planning estimates only. Actual tax treatment depends on jurisdiction, holding period, payroll handling, and your broader income picture.
6. What does breakeven share price mean?
It is the modeled sale price per share required to recover exercise cost, estimated taxes, and fees after accounting for the entered dilution impact.
7. Why can net proceeds be negative?
If exercise cost, taxes, and fees exceed the modeled sale value, the scenario produces a negative result. That helps identify unattractive exercise cases.
8. Can I use the exports for reporting?
You can export the result summary to CSV or PDF for sharing, but formal financial or tax reporting should rely on verified company and advisor data.