Calculator

1. 1

   Enter your co-founders' names

   Add between 2 and 5 co-founders. Each person will complete the survey independently, so their answers remain private until the final results screen.

2. 2

   Answer 10 weighted questions per founder

   Each founder works through 10 questions covering idea generation, business planning, domain expertise, time commitment, capital contribution, technical skills, network, risk tolerance, prior experience, and leadership role. Questions use a multiple-choice format, so there is no ambiguity.

3. 3

   Review the equity distribution

   Once all founders have answered, the calculator scores every response and converts the totals into equity percentages. You see a ranked breakdown card for each co-founder plus a detailed bar chart by category so you can spot any large contribution gaps.

4. 4

   Download the results as a CSV

   Hit the Download CSV button to save the full breakdown — individual scores, categories, and final percentages — and bring it to your co-founder conversation.

5. 5

   Use the data as your negotiation baseline

   Share the output with your co-founders. The data-driven breakdown acts as an objective starting point before drafting a formal co-founder agreement with a lawyer. It does not replace legal advice but removes the emotion from the opening conversation.

The entire process takes under 5 minutes. Results are calculated locally in your browser — nothing is stored or transmitted. To learn more about the methodology, see our articles on startup equity and co-founder agreements.

How should co-founders split equity?

Equity should reflect each founder's actual contributions across idea generation, capital invested, domain expertise, time commitment, execution risk, and future responsibilities. A weighted scoring model — like this free co-founder equity split calculator — is a widely accepted, objective starting point before finalising a formal shareholders' agreement.

What is a fair equity split for two co-founders?

A 50/50 split is the most common arrangement between two co-founders and is only fair when both founders contribute equally across idea, execution, capital, and commitment. If contributions are unequal, splits like 60/40 or 70/30 better reflect reality. Use this startup equity calculator to get a data-driven recommendation.

Can I use this equity calculator for more than two founders?

Yes. You can add up to five co-founders. Each founder completes the survey independently, and the calculator produces a full equity breakdown for all of them at once — showing every category score side-by-side.

Is the equity split legally binding?

No. The result is a data-driven starting point for negotiation. You should formalise your equity arrangement in a co-founder agreement or shareholders' agreement drafted with a qualified lawyer.

Should the person who had the idea get more equity?

Idea generation is one of ten weighted factors in this calculator. While the original idea matters, execution, commitment, capital, and expertise typically outweigh it in the long run. Most investors value traction and team quality far above the idea itself.

What factors does this equity calculator measure?

The calculator scores each founder across ten categories: idea generation, business planning, domain expertise, time commitment, capital contribution, technical skills, professional network, risk tolerance, prior startup experience, and leadership role. Each category carries a different weight reflecting its real-world importance.

Have a question that isn't covered here? Browse our startup blog for in-depth articles on equity, co-founder agreements, vesting schedules, and more.