Oklahoma City is 7.5 times larger than Cincinnati.
Area: 224 km2 calculated
Cincinnati is the third largest city in Ohio and the 28th largest city in the United States by metropolitan population and the county seat of Hamilton County. Settled in 1788, the city is located on the border between Ohio and Kentucky at the confluence of the Ohio River and the Licking River. Wikipedia
Area: 1,682 km2 calculated
Oklahoma City is the capital and largest city of the U.S. state of Oklahoma. The county seat of Oklahoma County, the city ranks 27th among United States cities in population. The population grew following the 2010 Census, with the population estimated to have increased to 610,613 as of July 2013. Wikipedia