Equity Vesting Schedule Calculator
Enter your shares, vesting period, and start date — see your cliff date, monthly vesting timeline, milestone dates, and what you'd keep if you left early. Free, no signup.
Last reviewed: March 2026
What Is Equity Vesting?
Equity vesting is the process by which you earn ownership of your stock options or shares over time. When a startup grants you equity, you don't own it all on day one — you earn it gradually, contingent on continued employment. Vesting exists to align employee incentives with company growth: the longer you stay and contribute, the more equity you own.
Most startup equity grants follow a 4-year vesting schedule with a 1-year cliff. This means nothing vests for the first 12 months (the cliff), then 25% vests all at once on your cliff date, and the remaining 75% vests in equal monthly installments over the next 36 months.
How the 4-Year Cliff Vesting Schedule Works
The standard 4-year, 1-year cliff schedule is the dominant structure in Silicon Valley startup grants. Here's the exact mechanics for a 10,000-share grant starting January 1, 2024:
Understanding the Equity Cliff
The cliff is the single most important date in your equity journey. It's a binary threshold: one day before the cliff, you have zero vested equity. One day after, you have 25% (for a standard 4-year grant). This is intentional — companies use the cliff to ensure they're retaining contributors long enough to verify the hiring decision was correct.
The cliff has significant financial implications for job-change decisions. If you leave 11 months into a job, you walk away with nothing. If you wait until month 13, you leave with 2,708 shares (cliff shares + one month post-cliff). The Timing Intelligence panel in this calculator always shows you your specific cliff countdown and the exact cost of leaving before vs. after.
Some grants (especially refresh grants for existing employees, or founder grants) have no cliff at all — vesting begins immediately from month 1. Others have unusually long cliffs of 18 or 24 months, common in later-stage companies or for senior executives.
How to Calculate Your Vested Shares
To calculate how many shares you've vested at any point in time, use this formula:
If today is before your cliff date
Vested shares = 0
On or after cliff date
Vested = Cliff shares + (months after cliff × monthly vest rate)
Monthly vest rate (post-cliff)
Monthly rate = (Total shares − Cliff shares) ÷ Post-cliff months
Example: 10,000 shares, 4-year vest, 1-year cliff, start date Jan 1 2024. On Oct 1 2025 (21 months in, 9 months post-cliff): Cliff shares = 2,500. Monthly rate = 7,500 ÷ 36 = ~208/month. Vested = 2,500 + (9 × 208) = 2,500 + 1,872 = 4,372 shares (43.7%).
Frequently Asked Questions
What is a vesting cliff?
A vesting cliff is the minimum employment period before any shares vest. The standard cliff is 1 year — before your cliff date, you have 0 vested shares. On your cliff date, 25% of a 4-year grant vests at once. After the cliff, remaining shares vest monthly. The cliff protects the company from immediately losing equity to someone who leaves after 3 months.
How many shares vest per month after the cliff?
On a standard 4-year grant with a 1-year cliff: 25% vests at the cliff (month 12), and the remaining 75% vests over 36 months. For 10,000 shares: 2,500 at cliff, then ~208/month. For 50,000 shares: 12,500 at cliff, then ~1,042/month. Use this calculator to see your exact schedule with correct rounding on the final month.
What happens to my unvested options if I quit?
Unvested stock options or shares are forfeited when you leave — they return to the option pool. Only vested shares are yours. If you quit before your cliff, you walk away with $0 in equity. After the cliff, you keep everything vested but forfeit the rest. Most options also have a 90-day exercise window after you leave — if you don't exercise in time, even your vested options expire.
What's the difference between ISO and NSO options?
ISOs (Incentive Stock Options) get preferential tax treatment: hold the shares for 2 years from grant and 1 year from exercise, and your gains are taxed at the lower capital gains rate. ISOs are only available to employees. NSOs (Non-Qualified Stock Options) tax the spread at exercise as ordinary income. RSUs vest without requiring exercise and are taxed as ordinary income at the vesting date.
What is single-trigger vs double-trigger acceleration?
Acceleration provisions speed up vesting on specific events. Single-trigger acceleration means your unvested shares accelerate on acquisition alone — common in founder grants. Double-trigger requires two events: typically an acquisition AND termination without cause. Double-trigger is more common for employee grants because it protects against an acquirer immediately forcing out employees to avoid their vesting.