513 Area Code: Cincinnati, Ohio

Cincinnati is the primary city of the 513 area code, the long-running designation for southwestern Ohio. Cincinnati sits along the Ohio River across from northern Kentucky, on a stretch of the river that has long anchored the city's working profile — the city's seven-hill geography, the river commerce, and a substantial concentration of corporate headquarters (Procter & Gamble, Kroger, Macy's, Fifth Third Bank) have shaped the local economy across multiple eras. The 513 footprint extends through Hamilton, Middletown, the western suburbs of Cincinnati, and the surrounding cluster of southwestern Ohio counties.

In records the directory has compiled for 513 numbers, other Ohio cities — Akron, Cleveland, Columbus, and Dayton — recur frequently. None of those are inside the 513 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Ohio and addresses linked across multiple cities. The directory currently documents 661 distinct prefixes within 513 in detail, a working subset of the prefix population the code carries.

Cincinnati's home values come in below the US median, with median household income running below the national figure. The city's median age sits well under the US reading, in the low thirties, shaped in part by the substantial student population at the University of Cincinnati. Population places Cincinnati among the larger cities in Ohio — substantial enough to anchor a metropolitan area that extends across the river into Kentucky and Indiana, with the broader 513 footprint covering the Ohio side of the metro.