Profit sharing should be on the basis of:
1. Skills
2. Experience
3. Contribution to the idea
4. Contribution in the execution
5. Potential Contribution in (a) revenue and (b) traction
6. Initial investment
7. Future scope of investment
8. Industry relationships
9. Partnerships
10. Duties accepted & future duties/responsibilities
11. Degree of risk
12. Sacrifice for the business
13. Balancing factors
14. Happiness Quotient
15. Success Quotient
16. IQ
17. EQ
18. Science & Technology Quotient
19. Key Drivers (Secret Sauce)
20. Moral ratings

My team have developed a formula for finding out the right percentage of share to be allotted to each member. You may setup a call so that I can take up input and suggest the appropriate percentage.

Thanks
Shishir