This page lists the top 25 public libraries in the United States by four specific statistical measures; namely, by size of population served, by the size of the library collection, by the number of times items in the collection were checked out, and number of visits to the library.
These public library statistics come from the Public Libraries in the United States Survey of the Institute of Museum and Library Services (IMLS), the primary source of federal support for the nation's libraries and museums. The Public Libraries Survey (PLS) provides statistics on the status of public libraries in the United States. The data are collected from approximately 9,000 public libraries with approximately 17,000 individual public library outlets in the 50 states, the District of Columbia, and outlying territories.
Specifically, all four tables were created with the PLS Fiscal Year 2016 data.
For Population of the Legal Service Area, the PLS Fiscal Year 2019 Data Element Definitions state: The number of people in the geographic area for which a public library has been established to offer services and from which (or on behalf of which) the library derives revenue, plus any areas served under contract for which the library is the primary service provider.
Under Collection Expenditures: This includes all operating expenditures from the library budget for all materials in print, microform, electronic, and other formats considered part of the collection, whether purchased, leased, or licensed. Total Collection Expenditures: This is the sum of Print Materials Expenditures, Electronic Materials Expenditures, and Other Materials Expenditures.
PLEASE NOTE: In contrast to the twenty-five public libraries listed below that serve in excess of 1,000,000 people, it's important to keep in mind that these are the anomaly; nearly 80% of the public libraries in the United States serve populations under 25,000 people.
Hillsborough County Public Library Cooperative, FL
Hawaii State Public Library System, HI
San Diego Public Library, CA
Dallas Public Library, TX
Riverside County Library System, CA
Orange County Library District
San Bernardino Public Library, CA
Top 25 public libraries by holdings
Data from Institute of Museum and Library Services, Public Libraries Survey (PLS) Fiscal Year: 2016
For Library Collection, the PLS Fiscal Year 2016 Data Element Definitions state (slightly edited): This section of the survey collects data on selected types of materials. Under this category, report only items the library has acquired as part of the collection, whether purchased, leased, licensed, or donated as gifts.
There are also specific definitions for Print Materials, Electronic Books (E-Books), Audio - physical units, and Video - physical units.