20% is not the normal minimum in the US. Edit: here are some supporting links. 15-20% suggested with 20%+ recognized as a minority opinion and for extra good

20% is not the normal minimum in the US. Edit: here are some supporting links. 15-20% suggested with 20%+ recognized as a minority opinion and for extra good service: http://www.cnn.com/2015/03/02/travel/experts-guide-to-tipping-in-the-united-states/ http://www.cnn.com/2015/03/02/travel/experts-guide-to-tippin... The highest tipping state averages 17% and the lowest averages 15%: https://qz.com/189458/the-united-states-of-tipping/ https://qz.com/189458/the-united-states-of-tipping/