The practice of tipping creates a lot of awkward moments. When is it customary to tip a person who helps you? And what’s a typical tip for a waiter, cab driver, hotel housekeeper, hair stylist or barber? Fifteen percent? Twenty percent? A fixed amount?

Some consumers detest the whole concept of tipping. Why don’t restaurants, hotels, salons, and dozens of other businesses where tipping is expected just charge higher prices and pay their workers more? It would spare their workers the risk of having lousy days of earnings at the hands of unusual strings of tipping stiffs. And it would spare their customers the process of deciding whether a tip is appropriate, the numbers crunching to calculate the right amount, and the often weird interpersonal dynamic that tipping creates.

Anti-tipping sentiments prevailed in the U.S. at the beginning of the 20th century: Between 1909 and 1918, seven states passed anti-tipping laws—although all of them were repealed by 1926. In many countries, tipping is much less prevalent than in the U.S. In Japan, for example, tipping at restaurants is not expected. Restaurants in Germany and France include a service charge in the bill and any additional tips are usually small—rounding up the bill and leaving change or perhaps five percent more for special service.

In terms of economic theory, there are good arguments in favor of tipping. When tipping is customary, it creates incentives for waiters and other types of workers to deliver quality service. Of course, rather than relying on a gratuity system, restaurants, like many other businesses, could monitor the quality of each waiter’s service and reinforce good performance with higher wages. But at least in theory, having each customer observe and compensate according to quality creates a more nuanced feedback system. And some people like tipping because it provides an easy concrete way to say thank you for very good service. (There’s another reason service industry employers and workers prefer a tipping system, even if it’s chaotic: Tips are often undertaxed.)

However, for tips to work as financial incentives for good customer service, there have to be tipping norms to which customers generally adhere, with customers consistently tipping more when they receive better-than-normal service. Apart from a sense of fairness and social responsibility, consumers may also tip to ensure future good service if they plan to return to the business, and possibly be served by the same worker. But many waiters, hotel workers, cab drivers, and other service providers—especially in tourist areas—count on tips from customers they never expect to see again. Another reason for tipping may be to avoid the embarrassment and discomfort of being viewed with contempt by the service worker.

Whatever the reason, most consumers do follow broad tipping norms. But it’s not always easy to know the norms.

The table below provides guidance. We asked Consumers' Checkbook subscribers to share their practices for the most common tipping situations, and nearly 2,000 subscribers completed our survey. We have examined tipping only in the U.S. and only routine tipping at the time of service, rather than holiday tipping (Emilypost.com offers excellent guidance for these tipping situations).

Although we found substantial differences in tipping practices among individual survey respondents, Consumers' Checkbook subscribers are generally in line with the recommendations on tipping-advice websites. There were also no significant differences in tipping practices across the seven metro areas where we publish Consumers' Checkbook, nor were there significant differences in tipping practices across income levels. Age didn’t affect tipping practices—even between subscribers younger than 35 and those older than 75. And subscribers who do a lot of traveling or dine out frequently don’t tip more than those who seldom travel or eat out.

Some studies have found that most consumers tip very consistently, regardless of service quality. However, for the incentive aspects of tipping to work, customers must tip more or less than the norm when they get extraordinarily good or bad service. Consumers' Checkbook subscribers do sometimes significantly vary their tip levels in response to variations in service quality. While the average restaurant tip among our survey respondents was 17 percent, the average in cases of exceptionally good service was 21 percent, and the average in cases of unusually poor service was 11 percent.

When asked what tip they leave for exceptionally poor service, most said they always leave something, but 37 percent said they have at least once left nothing. A few respondents mentioned leaving only pocket change to make it clear the skimpy tip was no oversight. Several mentioned tipping normally but speaking to restaurant management.

Many cautioned about the difficulty of determining whether poor service was really the fault of the service worker (as opposed to kitchen staff, for example).

A consistent refrain was that while consumers don’t like the custom of tipping, when tipping is the norm it must be recognized as an essential part of the service worker’s income, and leaving a fair tip is every customer’s responsibility.

Tipping Tips

Surveyed Consumers' Checkbook subscribers tip: EmilyPost.com suggestion
5% tip this or less Average tip 5% tip this or more
Waiter: percent for average service 14% 17% 20% 15-20%
Waiter: percent for exceptional service 18% 21% 25%  
Waiter: percent for poor service 0% 11% 15%  
Bartender: percent of bill 0% 15% 20% 15-20%
Bartender: amount per drink $.50 $1 $2 $1-$2
Barista: amount $0 $.60 $2  
Restaurant delivery: percent of bill 5% 14% 20% 10-15%
Restaurant delivery: amount for $20 order $2 $3 $5 $2-$5
Restaurant delivery: amount for $80 order $4 $11 $20  
Takeout restaurant order: percent of bill 0% 4% 15% 0-10%
Hotel bellhop/porter: amount per bag $1 $2 $5 $1-$2
Hotel housekeeper: amount per day $0 $3 $6 $2-$5
Skycap: amount per bag $1 $2 $5 $1-$2
Coat checker: amount per coat $.50 $1 $3  
Parking lot attendant: amount for retrieving car $0 $2 $5  
Parking valet: amount for retrieving car $1 $3 $5 $2-5
Taxi driver: percent of fare 10% 15% 20% 15-20%
Barber: percent 5% 18% 30%  
Hair stylist: percent 9% 18% 35% 15-20%
Hair washer at salon: amount $0 $6 $20  
Manicurist: percent 0% 16% 25% 15-20%
Massage therapist: percent 0% 15% 21% 15-20%
Dog groomer: percent 0% 11% 20%  
Furniture delivery: amount $0 $8 $20  
Car wash: amount $0 $3 $10