Just like in the rest of the USA, it’s normal to tip in the waiters in restaurants and bars in Hawaii. Hawaii does indeed have a tipping culture.
The standard tipping amound for adequate services is usually 15% and you can tip 20-25% for outstanding service. Sometimes, it can come across as insulting to tip less than 15% for service. We would recommend always to give a tip of at least 15%.
Not only waiters in Hawaii you can tip, but also a tour guide. The amount you should tip can be based on the length of the tour. For example, tip $5 per person for a 1- to 2-hour group tour; $10 per person for a 2- to 4-hour group tour; and $20 per person for a 4-hour to full-day group tour.