When I was young 10% was the standard tip for good service. Then somewhere along the way it turned into 15%. Now I just read that 15% is considered an insult. 20% is now the appropriate tip for good service. This doesn't make sense to me. As the price of food goes up then the amount a server earns at 10% goes up along with it. So servers get their cost of living tip raise simply by keeping the tip at 10% and letting the cost of food go up. Why does good service demand a 20% tip now when it was perfectly adequate at 10% years ago. Remember, the amount the server takes home at 10% has gone up with inflation so they actually have gotten raises along the way.