Various facts applying I have heard as little as 8% and as much as 30% for a typical Angel round. Venture backed Seed funding usually being within that range.
It's good to be flexible but to have enough of a belief in what you are doing that if the first offer isn't the right offer you are willing to walk away in search of the right deal. Having a ceiling is generally good.
You want to make sure you can last 2-3 rounds before giving up a majority stake.
