Day Zero Valuation
nostrademons: The question's basically meaningless - startup valuation is fuzzy enough when VCs invest after launch, revenue, sometimes profits.  How could you come up with a number before you've even launched?I suspect that the prospective cofounder is trying to figure out how much of the startup he will end up owning.  He knows how much he is worth in dollar terms; divide that by the present value of the startup and you get the percentage of ownership that vests per month/year/whatever.  So if his present salary is worth $100k/year, and the startup is currently valued at $1M, and his shares vest over 4 years, and the startup's value remains constant over those 4 years (unlikely, but for the sake of calculation...), he's thinking he'll get 40% of the company.This is an incredibly awkward way to think about valuation and equity splits.  If this is really his concern, I'd say just make him an offer for the proportion of equity you're going to give him.  It should be based on how much he'll improve the startup's chances in the future, not on some made-up numbers for present salary & valuation (which is basically meaningless).  So if you think he'll contribute as much as you guys will, and he's crucial to the startup's success, give him shares that are nearly equal to yours.  If you don't think that, I'd suggest not bringing him on as a cofounder at all rather than trying to work out some lower equity number.  Don't worry too much about what you've already done: trust me, the vast majority of work is ahead of you...