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Free ForeverNo SignupVesting IncludedUpdated 2026

Founder Equity Calculator

Calculate your vested equity, current stake value, and how dilution affects your ownership over multiple rounds.

Founder equity is your ownership stake in the company, expressed as a percentage of fully-diluted shares. It determines your economic upside at exit. Equity typically vests over 4 years with a 1-year cliff — you earn your shares over time rather than owning them all upfront.

Total shares granted to you as a founder

All shares in the company including options and other shareholders

Total vesting period (typically 48 months / 4 years)

Months before first vesting event (typically 12 months)

How long you have been at the company

Latest post-money valuation

$

The Formula

Vested % = (Cliff ÷ Vest Period) + ((Months Served − Cliff) ÷ Remaining Vest Period) × (1 − Cliff%)

In plain English

After the cliff, shares vest monthly. Cliff shares vest all at once at the cliff date, then monthly thereafter.

Worked Example

48-month vest, 12-month cliff, 18 months served. Cliff = 25%. Post-cliff = 6÷36 × 75% = 12.5%. Total vested = 37.5%.

How Founder Vesting Works

Founder vesting is not just an investor requirement — it's essential team alignment. If a co-founder leaves after 6 months, vesting ensures they take only the equity they've earned, not their full grant. Without vesting, a departing co-founder owns equity in a company they no longer work in.

Standard 4-year vesting with 1-year cliff means: nothing vests until month 12, then 25% vests all at once (the cliff), followed by 1/36th of remaining shares each month for 36 more months. Investors will require this structure.

4 years

Standard vesting period

1 year

Standard cliff period

25%

Shares vesting at cliff

1/36

Monthly vest post-cliff

Founder Equity Norms by Stage (2026)

StageFounder OwnershipVestingCliffStatus

Pre-seed (solo)

90–100%4 years1 year

Pre-seed (2 founders)

80–90% split4 years1 year

After seed

60–75% combined4 years1 year

After Series A

40–60% combined4 years1 year

Source: Y Combinator Founder Agreement Templates · Carta Benchmarks 2025

Common Mistakes

⚠️

Equal founder split without regard to contribution

A 50/50 split between founders sounds fair but rarely is. Weight the split based on who's full-time, who has the core idea, who has the technical skills, and who has the most to lose. Unequal splits done fairly early prevent resentment later.

⚠️

Skipping vesting to avoid the conversation

Not implementing vesting to avoid an awkward co-founder conversation is a serious mistake. If one co-founder leaves in year 1 without vesting, they own 40% of the company while contributing nothing. This kills the startup.

⚠️

Not negotiating accelerated vesting on acquisition

Single or double trigger acceleration on M&A is standard to negotiate. Without it, an acquirer can effectively defer your equity by keeping you employed for the rest of your vesting period on low comp.

Frequently Asked Questions

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