How much do you tip? How much should you tip? Maybe you don’t tip at all?

The average tip in Washington state is 17.51% of the check, about 1.3% below the national average. Only California residents tip less, 17.4%.

TradingPedia surveyed more than 2,000 adults exploring tipping behaviors across the United States in late February, and found that the average tip for all goods and services is 18.85%. More than 17% of respondents said tipping is expected too frequently, but only 7% said they never tip. Interestingly, men tend to tip slightly higher than women.

Tipping is, admittedly, murky. There’s an established culture of tipping at sitdown restaurants (many in Seattle, including those at Ethan Stowell restaurants, expect no gratuity but automatically add a 22% surcharge to the bill). But what about takeout? Food or furniture delivery? How about for counter service at a coffee shop? It’s not one size fits all, nor should it be.

The survey unearthed some interesting facts:

• Women tip more consistently at more places, but men typically leave higher tips.
• Millennials tend to be the most generous tippers. Baby Boomers (those older than 61) are the stingiest, leaving on average a tip of only 16.4%.
• About 57% of respondents believe tipping should depend on quality of service. Almost 40% want to eliminate tipping altogether in favor of higher wages. Two-thirds of respondents dislike recommended tipping percentages (my friend labels it “social pressure”) while only 6% find them helpful.

At an average of 21.25%, Delaware residents tip the most.