If there were no other factors (money, space, etc) how many kids could you handle having?

I am capped at my two, if I had a third I would lose my mind. I don't know if it's because my girls are really needy (especially my 3 year old) but I just don't think I could handle any more kids, mentally! I sometimes think: "aww a baby, maybe one more" and then we have a play date or something and I'm all like "nope, I'm good!" I honestly don't think I could be the best mom if I had any more kids.