How much equity should you give a co-founder?

If he's really a cofounder, meaning you haven't even incorporated yet, and he has the same qualifications and is going to work as hard as the other founders, you should give him pretty close to the same amount of stock.

So that's actually an easy question. The harder question is how much stock to give to your early hires.

Weird question. How much value is he going to bring in? How critical this guy is for your organization?

Do you expect us to decide for you? :-) Okey. Give him 43.75% and a written guarantee of a personal parking spot (a-la Mr. Lumberg in "Office Space") when you become next google :)