Ask HN: How to Split Revenue in a Startup?

Not enough information but maybe this can help: If the "non technical guy" ends up marketing and bringing in all or most of the paying customers, or handling all the bureaucracy, or managing staff, etc, then he might think the same about the "technical guy".

Are you both starting the project at the same time? If so, 50/50 is fair, neither of you has added any value up to this point.

If you've already built out the product and are just now bringing in a non-technical person you can possibly negotiate a better percentage for yourself. Even better if you've already brought in some revenue.

Go to the next highest fraction then? E.g. if it's just you and one other person give them a third, you and two others give them each a quarter, etc.

(Just an idea, I'm 100% an armchair quarterback here.)

50/50

If it feels strange. Hire that guy, pay his salary and split 100/0.