How Much Should We Tip Our Tour Guides?

Posted by Alternative_Ethereum@reddit | AskAnAmerican | View on Reddit | 40 comments

We are a family of 4 going from Asia to USA next week. We'll be taking various "tours", such as --

The tour price we paid for our family are: ACT more than USD 300 , GV more than USD 700

The question is: Are we really supposed to tip (up to) 20% of the tour price, i.e., ACT = USD 60 and GV = USD 140 assuming their service is acceptable?

Last but not the least, how much would (did) you pay as a native American for similar tours?