About the Equity Vesting Schedule Calculator
This vesting schedule calculator shows how many of your shares or stock options have vested on any date. Enter the number of shares granted, the vesting start date, the total vesting period, the cliff, and whether vesting happens monthly, quarterly or annually. It returns your vested and unvested shares on the date you choose, the next vesting date and amount, the date you become fully vested and a complete schedule of vesting events.
It works for startup employees with option grants, founders with restricted stock subject to repurchase, and anyone with RSUs on a time-based schedule. The most common startup schedule is four years with a one-year cliff: nothing vests for the first 12 months, then 25% vests at once, and the rest vests in equal monthly installments over the following 36 months.
You can also model acceleration: if a change of control (and, for double-trigger terms, a termination) happens on the as-of date, a percentage of the unvested shares vests immediately. Vesting events fall on the same day of the month as the start date (or the last day of shorter months), and fractional shares are rounded down on each event, which is how most equity plans work.
With the default inputs, the vested shares is 18,000. Change any value above to recalculate instantly.
How to use the equity vesting schedule calculator
- 1Enter the number of shares or options in your grant and the vesting start date.
- 2Choose the total vesting period and the cliff length (12 months is standard).
- 3Pick monthly, quarterly or annual vesting after the cliff.
- 4Set the date you want to check and any acceleration that applies.
- 5Review vested shares, the next vesting date and the full schedule of events.
Formula and method
m is the number of whole months of service completed since the vesting start date, N is the total vesting period in months and f is the vesting frequency (1 for monthly, 3 for quarterly, 12 for annual). Before the cliff nothing vests. At the cliff, all the months served so far vest at once — for a 12-month cliff on a 48-month schedule that is 25%. After that, shares vest in proportion to the months completed, counted at each vesting interval.
Cumulative vested shares are rounded down to whole shares at each event, and the final event always brings the total to 100%. Acceleration adds a percentage of the shares still unvested on the as-of date: single-trigger acceleration happens on a change of control alone, double-trigger requires both the change of control and a qualifying termination.
- m
- Whole months of service completed
- N
- Total vesting period in months
- f
- Vesting frequency in months (1, 3 or 12)
- cliff
- Months before the first vesting event
Worked examples
48,000 options, 4 years, 1-year cliff, checked after 18 months
After the cliff on 15 Jan 2027, 12/48 = 12,000 options vest; then 1,000 vest each month. By 15 Jul 2027 (18 months) 18,000 have vested — 37.5% — worth $36,000 at $2 per share. The next 1,000 vest on 15 Aug 2027.
One day before the cliff
Only 11 full months have been served, so nothing has vested. Tomorrow the cliff releases 12,000 options (25%) at once.
Quarterly vesting checked at 20 months
With quarterly vesting only completed quarters count: 20 months rounds down to 18, so 18/48 × 48,000 = 18,000 have vested. The next quarter at month 21 adds 3,000.
Double-trigger acceleration of 50% at 18 months
18,000 options have vested by the as-of date; half of the 30,000 unvested options (15,000) accelerate, bringing the total to 33,000 vested.
Frequently asked questions
What does 4-year vesting with a 1-year cliff mean?+
Nothing vests during the first 12 months. On the one-year anniversary 25% vests at once, and the remaining 75% vests in equal monthly installments over the next 36 months, so you are fully vested after four years.
What happens to unvested shares if I leave?+
Unvested options are usually forfeited when you leave, and unvested restricted stock can be repurchased by the company, typically at the original price. Vested options normally must be exercised within a post-termination window, often 90 days.
What is single-trigger vs double-trigger acceleration?+
Single-trigger acceleration vests some or all unvested shares when the company is acquired. Double-trigger requires two events — an acquisition and your termination without cause (or resignation for good reason) within a set period — and is far more common because acquirers want to retain the team.
Do founders have vesting schedules too?+
Yes. Investors almost always expect founder shares to vest, commonly over four years with a one-year cliff, sometimes with credit for time already worked. It protects co-founders from someone leaving early with a large stake.
Should I file an 83(b) election?+
If you receive restricted stock that vests over time in the US, an 83(b) election filed with the IRS within 30 days of the grant lets you be taxed on its value at grant rather than as it vests. It does not apply to ordinary stock options; get tax advice for your situation.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.