Written by: Libby Gremaud

Have you ever needed a book in the library but couldn’t understand what the random numbers and letters in the call number meant? Have you ever gotten lost in the stacks while looking for a book? The call numbers can be confusing for someone who isn’t familiar with them, but once you learn how it works, you can find any book you want in the library! 

The library uses a few different systems of call numbers. If it begins with a letter, it is a Library of Congress call number, which is the main system used in academic libraries. These organize the books into subjects, with each grouping of numbers representing a more specialized topic. For example, the letter J is for Political Science books. The second letter represents an even more specific topic. In particular, JC is the subcategory of political theory under the broader category of J for political science. What is convenient about this system is that similar topics will be located next to each other in the library. 

A few collections in Mizzou Libraries use a different system like the Dewey Decimal system, which are all number codes.

To figure out where the book you’re looking for is, first see whether it uses the Library of Congress system or the Dewey decimal system. The Library of Congress sorts its books alphabetically, so the letters that appear at the front are going to be important for finding where the book would be located. This list guides you to where in the stacks they are located: 

After going to the floor where your book is located, look at the signs on the ends of the stacks to figure out which aisle your book is in. The books are sorted by ascending number order which comes after the letters in the call number- make sure you read each number as a whole number. 300 versus 3000 would be decently far apart in the stacks. Those numbers will be printed on the spines of the books, so once you have the right aisle, go down the row and read the spines. When you’ve found the correct number, down to the last digit, there’s your book! 

If your book uses the Dewey Decimal system, there’s only a few places in the library where it might be. For the most part, books with these numbers are in 4 East or the Depository. The Depository is where all of the overflow books are located, which is off campus and doesn’t have public access. In order to retrieve a book from the Depository you have to request it and it will be sent to the library for you to pick up. If the call number for your book is 353.8, that means it will go to the Government Documents section of the library, which is located in 1 East.

While finding a book may seem difficult, once you figure out how the call numbers work, you’re good to go! Of course, if you ever need help finding your book, feel free to visit the Peer Navigator desk on the first floor or ask for help through the Libraries Chat. For more information on how to find a book, visit the Locate a Book Using its Call Number: How to Find a Book page on the library website.