Portlanders and Oregonians don't necessarily break the bank when they tip their servers.

Then again, they're not the biggest skinflints either. Close, but not the biggest.

So reveals data compiled by Square Inc., which provides transaction software and related credit card-processing equipment to retailers throughout the United States. The data was culled from roughly 2 million transactions recorded in July.

View slideshow: The U.S. cities with the best tippers

The national average for tipping was 16.4 percent. The data came from retailers ranging from small businesses to enterprises as large as Whole Foods (NASDAQ: WFM) and Starbucks (NASDAQ: SBUX).

Portland came in at 16.1 percent, ranking 16th among the nation's 30 largest cities. Oregonians all told tip smack at the national average, at 16.4 percent. However, that figure ranks only 35th among the 50 states and the District of Columbia.

Squared's rankings included a list of all U.S. states as well as a separate list of the the 30 largest U.S. cities, comparing average gratuity rates tracked in July. Idaho's restaurant goers outpaced their peers throughout the country with an average gratuity rate of 17.4 percent, while Hawaii ranked last at 14.8 percent.

Among the top 30 cities, Cleveland ranked last, at 14 percent, well behind both San Francisco and Miami, at 14.6 percent. Seattle ranked 22nd, at 15.7 percent.

The full rankings are in the slideshow above.

The Portland Business Journal is a KGW News partner.