For restaurant wait staff, the gratuity is calculated on the total before tax is added. Ten percent is the minimum, even for poor service. Average service should receive a 15 percent tip, while excellent service calls for 20 percent.
Other restaurant staff also receive gratuities. A headwaiter often gets a percentage of the wait staff's tips; therefore, if there is a headwaiter, customers should tip the wait staff more. A wine steward is typically given 15 percent of the cost of the wine. A bartender receives 15 to 20 percent of the total drink tab but no less than 50 cents for a soda and $1 for an alcoholic beverage.