I am in favor of an even split, but there can be problems. My wife and I used to eat out regularly with another couple, a multi-millionaire doctor and his wife. I am not wealthy. We always split but there were a few episodes; one place we often went to took cash only; the bill would come and I put down 1/2 and approximately a 20% tip. He always put down 1/2 plus $1 (he could have been leaving this little at other places, but I had never looked at what he was writing on the credit card receipt). A couple of times, when we went to places where he knew I got 20% off, due to belonging to a dining plan, he would ask me to pay it all and said that he would later pay me back, in cash, his 1/2, less 20%. He always "forgot" however. Then, the couple began having marital problems. They would still sometimes "date" with us but we knew they were living separately. While they were in that status, the wife began to order two appetizers and one main course. She would eat both appetizers, take one bite of the main course and ask the waiters to box up the left-overs for her to eat later. Although everyone one else only had one appetizer, I still paid 1/2. They are back together now, but have moved away. It is a bit of a relief. I was not really upset about being taken advantage of as it did not amount to a great deal; it was more of being a bit surprised in view of his great wealth and wondering why he felt he needed to take slight advantage of a friend.