The method
How it is worked out
Founder share = available founder equity × individual contribution score ÷ total contribution scores
- available equity
- 100% minus option pool
- score
- A relative contribution score agreed by the founders
Founder Equity Calculator
Model a simple founder equity split using contribution weights such as cash, time, idea, sales and product work. The result updates as you type so you can compare scenarios quickly.
Keep in mind
What it leaves out
- Not legal adviceFounder equity should be documented by lawyers and tax advisers.
- VestingVesting, cliffs and leaver provisions are not modelled.
- Subjective scoresContribution weights are negotiation inputs, not objective facts.
Use the calculator to compare scenarios rather than as a guaranteed forecast.
About the Founder Equity Calculator
Sketch a provisional ownership split between founders before discussing the actual share agreement. It is useful when collaborators want to make their assumptions about contributions explicit rather than defaulting to an arbitrary equal split.
How it works and an example to tryShow less
How to use the result
The model allocates the equity available to founders in proportion to contribution scores entered for each person, including the dimensions the tool asks about. An option pool or reserved share reduces the founder allocation before the proportional split. Scores are subjective and do not account for vesting, legal ownership, future financing or voting rights.
Example to try
Start with two equal partners, then reserve a 10% employee option pool. Change one founder's contribution weights and observe the revised allocation. Record the assumptions separately and obtain appropriate legal documentation before issuing shares.
Put it to work
Try it on a real situation
Load an example
What moves the result most
Worked out from your figures above. Tap a row to try it.
Who uses it, and when
Co-founders about to incorporate, teams adding a technical or commercial partner after launch, and advisers helping founders have a structured conversation about contribution.
Mistakes worth avoiding
- Splitting equally by default to avoid a difficult conversation.
- Forgetting vesting, so a departing founder keeps a large stake.
- Treating the initial idea as worth more than the years of work to follow.
Questions
What does the Founder Equity Calculator do?
Model a simple founder equity split using contribution weights such as cash, time, idea, sales and product work.
How should I use the result?
The model allocates the equity available to founders in proportion to contribution scores entered for each person, including the dimensions the tool asks about. An option pool or reserved share reduces the founder allocation before the proportional split. Scores are subjective and do not account for vesting, legal ownership, future financing or voting rights.
Does TechBullion store the information I enter?
The core calculation or transformation runs in your browser. Normal website security and analytics may still record page-level events, but the tool does not need to create a public record from your inputs.
What mistakes do people make with a founder equity calculator?
Splitting equally by default to avoid a difficult conversation. Forgetting vesting, so a departing founder keeps a large stake. Treating the initial idea as worth more than the years of work to follow.
Is the result guaranteed?
No. Use the result as a practical check or planning aid and verify important decisions with the relevant primary source, provider or professional advice.
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Calculator results are estimates based on the figures entered and are not financial, investment, legal or tax advice.