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Employee Stock Options Calculator

Project the value of your stock options across vesting, current FMV, and exit scenarios. Useful for offer-letter math, exercise decisions, and exit planning.
Value at projected exit
$2.42M
Intrinsic value today
$63K
Vested shares
25,000 (50%)
Cost to exercise vested
$38K
Vesting schedule
Month 12
$606K
Month 24
$1.21M
Month 36
$1.82M
Month 48
$2.42M
Reality checkYou're 50% vested. Exiting today would mean walking away from $1.21M of unvested upside.

What is the employee stock options calculator?

This calculator turns your stock-option grant into clear numbers: how many shares are vested today, how much they'd be worth at a projected exit, what it costs to exercise, and what's still unvested.

It works for both ISOs (incentive stock options, US-only) and NSOs (non-qualified stock options). Tax math varies by jurisdiction and exercise timing — talk to a CPA before any actual exercise.

Why this matters for founders & operators

Most employees underestimate the value of their options because the math is intimidating. Worse, many leave money on the table by:

  • Quitting just before their cliff (zero vested = zero value)
  • Not exercising before leaving (PTE windows are usually 90 days)
  • Ignoring the AMT impact of exercising ISOs at low FMV
  • Not understanding the difference between strike price and FMV

Use this calculator before signing an offer (to compare grants properly), before quitting (to know what you're walking from), and before exercising (to estimate cost vs. potential return).

How to use this calculator

  1. 1
    Enter your grant

    Number of options and strike price come from your option grant agreement. If you have RSUs instead, ignore the strike price field (set to $0).

  2. 2
    Add the current FMV

    Fair market value per share, typically from your company's most recent 409A valuation or post-money price from the latest round.

  3. 3
    Estimate exit price

    What you think the share price will be at IPO or acquisition. Be realistic — not every startup 10x's. Many SaaS exits land at 1-3x the latest priced round.

  4. 4
    Set vesting + tenure

    Standard vesting is 4 years with a 1-year cliff. 'Months at company' is how long you've been there since your start date.

  5. 5
    Read the verdict

    Vested shares = what you'd keep if you left today. Cost to exercise = what you'd pay to convert vested options to shares. Value at exit = the headline number, but only realized at a real exit event.

FAQ

Should I exercise my options early?+
Maybe. Early exercise can save tax (especially with ISOs and AMT planning), but you put real money at risk for a possibly-zero outcome. Common framing: only early-exercise an amount you can afford to lose entirely.
What's a 90-day post-termination exercise window (PTE)?+
After you leave a company, you typically have 90 days to exercise vested options or they expire. Some companies extend this to 7-10 years. Check your option agreement carefully.
What's the difference between FMV and strike price?+
Strike is what you pay per share to exercise (set when granted, fixed). FMV is the current value (changes with each round or 409A). Your gain per share = FMV - strike, paid only at sale.
Are RSUs better than options?+
Different. RSUs have no strike price (you don't pay to exercise), so they're worth something even at flat valuations. Options have leverage — they can be worth more if the stock pops, but zero if it doesn't. Late-stage companies usually grant RSUs; early-stage almost always options.
What's AMT and why should I care?+
Alternative Minimum Tax in the US can hit hard if you exercise ISOs at a high FMV. The 'spread' (FMV - strike) at exercise is treated as AMT income even though you haven't sold. Get a CPA before exercising any meaningful number of ISOs.