Work out what your employee stock options (ISOs or NSOs) are worth. Enter your grant, strike price, share price and vesting schedule to see how many options have vested, what it costs to exercise them and the potential gain at a future share price.
Last updated:
Your option grant
options
$/ share
$/ share
Latest 409A value for private companies, or the market price.
$/ share
Your scenario for a sale, IPO or future price.
Vesting schedule
years
months
Nothing vests before the cliff. 0 = no cliff.
months
%
Leave 0 for a pre-tax figure.
Enter your values to see the result.
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How to use the Employee Stock Option Calculator
Enter your grant: the number of options and the strike price from your option agreement.
Add share prices: the current fair market value (409A or market price) and the price you expect at an exit or sale.
Describe the vesting: total years, the cliff in months and how often options vest after the cliff.
Enter the months since your vesting start date to see how much has vested so far.
Read the results and scroll to the vesting schedule and price scenarios; download either table as CSV.
Stock option formulas
Vested options = options granted × vested months ÷ total vesting months (0 before the cliff)
Example: 10,000 options, a $2.50 strike and a 4-year monthly schedule with a 1-year cliff. After 18 months, 10,000 × 18 ÷ 48 = 3,750 options have vested. Exercising them costs 3,750 × $2.50 = $9,375. At a $20 exit price, all 10,000 options would be worth 10,000 × ($20 − $2.50) = $175,000 before tax.
Common vesting schedules
Schedule
At the cliff
After the cliff
Vested after 2 years
4 years, 1-year cliff, monthly
25% at month 12
1/48 (2.08%) each month
50%
4 years, 1-year cliff, quarterly
25% at month 12
6.25% each quarter
50%
4 years, no cliff, monthly
none
2.08% each month from month 1
50%
3 years, annual
33.3% at month 12
33.3% each year
66.7%
5 years, 1-year cliff, monthly
20% at month 12
1/60 (1.67%) each month
40%
Some companies use back-weighted schedules (for example 10%, 20%, 30%, 40%). Approximate those by checking the vested percentage your plan states and entering an equivalent number of months.
Frequently asked questions
How do you calculate the value of employee stock options?
The intrinsic value of an option is the share price minus the strike price, if that is positive. Multiply it by the number of options: (share price − strike price) × options. For example 10,000 options with a $2.50 strike and an $8 share price have an intrinsic value of $55,000. Options with a share price below the strike are underwater and have no intrinsic value.
What is a vesting cliff?
A cliff is a waiting period before any options vest. With the common 4-year schedule and a 1-year cliff, nothing vests for the first 12 months, then 25% vests at once on the 12-month anniversary and the rest vests monthly (1/48 per month) over the next three years.
How much does it cost to exercise stock options?
The exercise cost is the number of options you exercise times the strike price. Exercising 3,750 options at a $2.50 strike costs $9,375, plus any taxes that are due when you exercise.
What is the difference between ISOs and NSOs?
Incentive stock options (ISOs) are only for employees and can qualify for long-term capital gains treatment if you hold the shares at least 2 years from grant and 1 year from exercise, though the spread can trigger the alternative minimum tax. Non-qualified stock options (NSOs) are taxed as ordinary income on the spread when you exercise. This calculator shows pre-tax values; check the tax rules for your country.
What happens to unvested options if I leave the company?
Unvested options are usually forfeited when you leave. Vested options normally must be exercised within a post-termination exercise window, often 90 days, though some companies offer longer windows. Read your option plan for the exact rule.
Is the potential gain guaranteed?
No. The gain at an expected price is only a scenario. Private company shares may not be sellable until an acquisition or IPO, new funding rounds dilute ownership, and preferred shareholders may be paid first in a sale.
Is my data private?
Yes. The calculator runs entirely in your browser and nothing you enter is sent or stored on a server.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.