A new study reveals which Americans are willing to tip and just how much.

Creditcards.com spoke to a thousand people.

80 percent said they always tip at a restaurant -- averaging about 18 percent of the bill.

Customers paying with a card were also likely to tip more than those with cash.

Experts say it's proof we see don't see a credit card as "real money."

67 percent say they tip their hairstylists, 29 percent tip baristas, and 27 percent leave money for the housekeeping staff at hotels.

Although tipping has become pretty commonplace nowadays, there is still some uncertainty on when to tip.

Most people say they reward good service with a gratuity.

Edgar Macias, a 20-year-old waiter at El Jalisciense in Warner Robins, straps on his waist apron, and greets guests.

He relies solely on tips, and racks up about $600 a week.

He chose to become a waiter two years ago, so that he can balance his time between studying to be an engineer and saving money.

"In an hour as a waiter, I can probably make $20," said Macias.

Whether you order cocktail shrimp, the house special, or steak tacos, there's always a space at the end of the check that says tip.

"I tip more when the server is better. When the server comes here and you can tell she likes her job and she is trying her best to make your meal perfect, then I think I tip a lot more," said Robin Roughton.

Roughton and her friend Tonya White says they come to El Jalisciense once a week. White says convenience in paying with cards have become more common.

"Usually I do more on my debit card because I never have cash," said White.

Macias agrees; he notices a difference.

"I believe that people nowadays don't really carry cash. They usually have a debit cards and credit cards and maybe that's why they tend to leave more because of that option," said Macias.

For a tip guide, click here.