View source for Comparison of Dewey and Library of Congress subject classification

{{Short description|None}}
The Dewey Decimal and Library of Congress [[Library classification system|library classification systems]] are the two most common systems in the United States and among the most popular world-wide.<ref name=":3">{{Cite web |title=Cataloging Tools and Resources: Classification |url=https://libguides.ala.org/catalogingtools/classification |access-date=2025-08-21 |website=American Library Association |language=en}}</ref> These systems organize resources like books or other media by concept and assign [[Wiktionary:call number|call numbers]] that are, in part used to shelve and retrieve materials.<ref name=":29">{{Cite web |last=Francis |first=Frank C. |last2=Estabrook |first2=Leigh S. |date=2025-08-09 |title=The Dewey Decimal system |url=https://www.britannica.com/topic/library/The-Dewey-Decimal-system |access-date=2025-09-01 |website=Britannica |language=en}}</ref> The [[Dewey Decimal Classification]] (DDC) is used predominantly in public libraries in the United States while the [[Library of Congress Classification]] (LCC) is used primarily in academic libraries. 

== Characteristics ==
The Dewey Decimal Classification (DDC) was first published by [[Melvil Dewey]] in 1876,<ref name=":26" /><ref name=":2">Halstead, D. Kent. "[https://www.google.com/books/edition/DHEW_Publication_No_OE/0VQOAAAAIAAJ?hl=en&gbpv=1 Chapter IX: College and University Libraries: Bibliographic Access]" in ''Statewide Planning in Higher Education'' (''DHEW Publication'' No. 73-17002). Washington, D.C.: U.S. Government Printing Office, 1974. p. 400-408.</ref> and included a detailed justification for his use of [[decimal notation]].<ref>
{{Citation |last=Comaromi |first=John P. |title=The eighteen editions of the Dewey Decimal Classification |date=1976 |page=43 |location=Albany, N.Y |publisher=Forest Press Division, Lake Placid Education Foundation |isbn=978-0-910608-17-6 |ol=4881898M}}
</ref> DDC decimal notation id can be expanded or reduced as needed by libraries.<ref name=":26" /> It was designed for medium and small sized collections,<ref name="auto">{{Cite journal |last=Hjørland |first=Birger |date=2025 |title=Dewey Decimal Classification (DDC) |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1808-52452025000100321&tlng=en |journal=Em Questão |volume=31 |doi=10.1590/1808-5245.31.145068 |issn=1808-5245}}</ref><ref>[[Universal Decimal Classification]] (UDC) was created in 1905 based on ''DDC 5th edition'' to address the needs of large libraries.</ref> including those found in [[public libraries]], [[school libraries]], and small [[academic libraries]].<ref name=":1" /><ref name=":0" /><ref name=":27">{{Cite web |title=Call Numbers and the Library of Congress Classification System {{!}} HCC |url=https://henderson.kctcs.edu/current-students/student-resources/libraries/build-research-skills/call-numbers-classification.aspx |archive-url=https://web.archive.org/web/20250522105853/https://henderson.kctcs.edu/current-students/student-resources/libraries/build-research-skills/call-numbers-classification.aspx |archive-date=2025-05-22 |access-date=2025-08-28 |website=Henderson Community College |language=en-US |url-status=live }}</ref> It consists of ten numeric classes that represent broad fields of study.<ref name=":0">{{Cite web |title=Comparing LC and Dewey |url=https://home.olemiss.edu/~tharry/LC/LCvsDDC.html |access-date=2025-08-21 |website=University of Mississippi Library}}</ref><ref name=":1">{{Cite web |last=Moeller |first=Kimberly |date=2023-10-31 |title=Peer Navigator Corner: Library of Congress vs. Dewey Decimal System |url=https://library.missouri.edu/news/ellis-library/peer-navigator-corner-library-of-congress-vs-dewey-decimal-system |access-date=2025-08-21 |website=Library News |publisher=University of Missouri Libraries |language=en-US}}</ref><ref name=":25">{{Cite book |url=https://www.oclc.org/content/dam/oclc/dewey/resources/summaries/deweysummaries.pdf |title=Summaries DDC: Dewey Decimal Classification |publisher=OCLC Online Computer Library Center, Inc. |year=2003 |isbn=0-910608-71-7 |location=Dublin, Ohio |access-date=August 28, 2025}}</ref> Using numbers, each class is divided into ten divisions or subclasses.<ref name=":3" /><ref name=":25" /> During the cataloging process, each item is assigned a three-digit DDC number that represents class, division, and section, followed by a cutter number that identifies the author.<ref name=":24">{{Cite web |title=Basic Cataloging: Intro to Call Numbers |url=https://www.ipl.org/div-farq-deweyfarq/ |access-date=2025-08-22 |website=Internet Public Library |language=en-US}}</ref> For example, the call number 813.54 M37 includes 800 for the main class of literature, 810 for the division of American literature in English, 813 for American fiction in English, and the cutter M37 for the author.<ref name=":24" />

The Library of Congress Classification (LCC) was introduced in 1900, based on the collection of the [[Library of Congress]], the largest library in the world.<ref name=":26">{{Cite web |title=LibGuides: Cataloging Tools and Resources: Classification |url=https://libguides.ala.org/catalogingtools/classification |access-date=2025-08-28 |website=American Library Association |language=en}}</ref><ref name=":28">{{Cite web |last=Bullard |first=Eric |title=Library of Congress Classification (LCC) {{!}} Research Starters |url=https://www.ebsco.com/research-starters/library-and-information-science/library-congress-classification-lcc |access-date=2025-09-01 |website=EBSCO |language=en}}</ref> LCC was adopted by other institutions with larger or specialized collections, such as those found in academic libraries and [[research libraries]].<ref name="DeweyDiscord">{{Cite news |last=Lavallee |first=Andrew |date=July 20, 2007 |title=Discord Over Dewey: A New Library in Arizona Fans a Heated Debate Over What Some Call the 'Googlization' of Libraries |url=https://www.wsj.com/articles/SB118340075827155554 |access-date=May 25, 2013 |newspaper=Wall Street Journal |quote=}}</ref><ref name=":26" /><ref name=":1" /><ref name=":27" /> In 2019, 81 percent of US academic libraries and 93 percent of Nigeria's academic libraries used the Library of Congress Cataloging system.<ref>{{Cite journal |last1=Lund |first1=Brady |last2=Agbaji |first2=Daniel |last3=Tijani |first3=Solomon |last4=Omame |first4=Isaiah |date=2019-07-03 |title=Evaluating Knowledge Organization in Developed and Developing Countries: A Comparative Analysis of Dewey Decimal and Library of Congress Classification Scheme Preference and use in the United States and Nigeria |url=https://doi.org/10.1080/07317131.2019.1621563 |journal=Technical Services Quarterly |volume=36 |issue=3 |pages=249–268 |doi=10.1080/07317131.2019.1621563 |issn=0731-7131 |url-access=subscription}}</ref> LCC has 21 main classes, each designated with a letter of the alphabet, excluding I, O, W, X, and Y which are used to accommodate special needs of libraries that use the classification scheme.<ref name=":29" /><ref name=":0" /><ref name=":30" /> Its alpha-numeric call numbers include four parts: class/subclass, topic, cutter number, and publication date.<ref name=":1" /><ref name=":3" /> For example, HV4708 .R83 2011, where HV stands for social sciences, 4708 is the topic social welfare, .R83 is the cutter number which represents the author, and 2011 is the year of publication.<ref name=":1" />

Both classification systems are used to create a functional topical order of the resources on the library shelves.<ref name=":2" /> They vary in their notation: DDC is a numeric classification system, while LCC is an alpha-numeric system.<ref>{{Cite book |last=List-Handley |first=Carla J. |url=https://books.google.com/books?id=WbfRHoM0tnAC&dq=Comparison+of+Dewey+and+Library+of+Congress+subject+classification+-wikipedia&pg=PA5 |title=Information Research |date=2002 |publisher=Kendall Hunt |isbn=978-0-7872-9057-3 |page=5 |language=en |via=Google Books}}</ref><ref name=":28" /> LCC was developed specifically for the Library of Congress collection, while DDC was created as a system that could be adapted to a variety of library sizes and specialties.<ref name=":28" /> D. Kent Halsted noted, "Neither scheme is perfect nor will ever be."<ref name=":2" /> As with any classification system, both DDC and LCC include the bias of their creators; in this case, both systems were developed by white, Christian, male academic scholars in late 19th century America.<ref>{{Cite web |last=Christiansen |first=Andrew |date=2022-04-14 |title=SLCC switches library classifications |url=https://www.globeslcc.com/2022/04/14/call-number-change-dewey-decimal-library-of-congress-classification/ |access-date=2025-09-03 |website=The Globe |language=en-US |quote=Jon Glenn, director of library services, said we … wanted to make our system more equitable and inclusive, which isn’t really a question of which system was originally more biased, but rather which system...can be more easily improved upon...Any classification system is rooted in and biased by its creator and the time under which it was created. Glenn added that this applies to DDC and LCC, which were both developed in the United States during the 19th century by academic scholars who were white, male, and Christian.}}</ref>

There are various factors that determine which classification system a library uses.<ref name=":2" /> The global library cooperative [[OCLC]] notes that "A library should base its decision on close versus broad classification on the size of its collection and the needs of its users."<ref>{{Cite web |date=May 17, 2019 |title=Introduction to the Dewey Decimal Classification |url=https://www.oclc.org/content/dam/oclc/dewey/versions/print/intro.pdf |access-date=September 2, 2025 |website=OCLC |page=37}}</ref> Usually, the size of a library's collection determines whether it selects DDC or LCC.<ref name=":0" /> While DDC was designed for medium-sized libraries,<ref name="auto"/> LCC allows libraries with larger collections to be more specific or precise with classifications.<ref name=":0" /><ref name=":1" /><ref name=":2" /> Thus, DDC is preferred by institutions with collections under 200,000, while LCC is recommended if the collection includes more than 500,000 items.<ref name=":2" /><ref>As  Halstead notes, there are exceptions, with smaller institutions using LCC and larger institutions still using DDC.</ref> In the 1960s and early 1970s, many larger academic libraries changed from Dewey Decimal Classification to Library of Congress Classification.<ref>{{Cite journal |last=Shorten |first=Jay Shorten |last2=Seikel |first2=Michele |last3=Ahrberg |first3=Janet H. |date=April 2005 |title=Why Do You Still Use Dewey? Academic Libraries that Continue with Dewey Decimal Classification. |url=https://go.gale.com/ps/i.do?id=GALE%7CA132558147&sid=googleScholar&v=2.1&it=r&linkaccess=abs&issn=00242527&p=AONE&sw=w&userGroupName=anon%7E5d20fc72&aty=open-web-entry |journal=Library Resources & Technical Services |publisher=American Library Association |volume=49 |issue=2 |access-date=September 1, 2025 |via=Gale Academic OneFile}}</ref><ref name=":2" /> After converting the college's library from DCC to LCC in 2021, [[West Coast Baptist College|West Coast Baptist College's]] director of library services Alyssa Sultanik concluded, {{quote|LCC tends to divide resources into smaller subclasses and may be more suitable for larger collections. Several factors can play a part in the success of LCC, such as the practicality of LCC for academic libraries, the ease of use in a specialized collection, and the ability to grow for expanding libraries and the ability to easily add new topics as needed. The collection size, depth of the materials, and intended use of the library collection should be considered when choosing between classification systems...Smaller collections may be more suited for DDC because of the classification's more generalized nature.<ref name=":30">{{Cite journal |last=Sultanik |first=Alyssa |date=April 7, 2022 |title=Lessons learned about converting from Dewey Decimal Classification to Library of Congress Classification |url=https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=2322&context=tcl |journal=The Christian Librarian |volume=65 |issue=1}}</ref>}}

== Comparison ==
The following table compares the organization of resources by the Dewey Decimal and Library of Congress classification systems.<ref name=":25" /><ref>Scott, Mona L. and Alvey, Christine E. ''Conversion Tables: LC-Dewey, Dewey-LC''. 17th edition. Englewood: Libraries Unlimited, 1993. {{ISBN|9781563080173}}</ref><ref>{{Cite web |title=Map Dewey (DDC) to LC (LCC) Classification |url=http://www.questionpoint.org/crs/html/help/pl/ask/ask_map_ddctolcc.html |url-status=dead |archive-url=https://web.archive.org/web/20180503234601/http://www.questionpoint.org/crs/html/help/pl/ask/ask_map_ddctolcc.html |archive-date=2018-05-03 |access-date=2025-08-21 |website=Questionpoint.org |publisher=[[OCLC]]}}</ref><ref>{{Cite web |title=Map LC (LCC) to Dewey (DDC) Classification |url=http://www.questionpoint.org/crs/html/help/pl/ask/ask_map_lcctoddc.html |url-status=dead |archive-url=https://web.archive.org/web/20180419183147/http://www.questionpoint.org/crs/html/help/pl/ask/ask_map_lcctoddc.html |archive-date=2018-04-19 |access-date=2025-08-21 |website=Questionpoint.org |publisher=[[OCLC]]}}</ref><ref>{{Cite web |title=Library of Congress Classification Outline |url=https://www.loc.gov/catdir/cpso/lcco/ |access-date=2025-08-21 |website=The Library of Congress}}</ref><ref>{{Cite web |title=Dewey Decimal System – A Guide to Call Numbers |url=https://www.library.illinois.edu/infosci/research/guides/dewey/ |access-date=2025-08-22 |website=Information Sciences Virtual Library |publisher=University of Illinois Library}}</ref><ref>{{Cite web |title=Dewey Decimal vs. Library of Congress |url=https://library.kilgore.edu/dewey_lc.htm |url-status=dead |archive-url=https://web.archive.org/web/20240315110311/https://library.kilgore.edu/dewey_lc.htm |archive-date=2024-03-15 |access-date=2025-09-01 |website=Randolph C. Watson Library |publisher=Kilgore College |language=en-US}}</ref> It includes all 99 second-level (two-digit) Dewey Decimal classes (excluding 040), and all second-level (two-digit) Library of Congress classes. 

{|class="wikitable sortable "align="center"
!Dewey Decimal
!width=125|Library of Congress 
!width=550|Description
!{{Abbr|Ref.|References}}
|-
|'''000'''|| A, AZ, QA, TA, Z4–659
|[[Computer science]], [[knowledge]], and general works; [[history of scholarship]] and [[learning]]
|<ref name=":18">{{Cite web |title=Library of Congress Classification Outline – Class Q |url=https://www.loc.gov/catdir/cpso/lcco/lcco_q.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref name=":5">{{Cite web |title=Library of Congress Classification Outline – Class A |url=https://www.loc.gov/catdir/cpso/lcco/lcco_a.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref name=":22">{{Cite web |title=Library of Congress Classification Outline – Class Z |url=https://www.loc.gov/catdir/cpso/lcco/lcco_z.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|010||AI, Z1001–8999||[[Bibliography]], indexes
|<ref name=":22" />
|-
|020||Z4–1000.5 ||[[Library and information science|Library and information sciences]]
|<ref name=":22" />
|-
|030||AE, AG, AY ||[[General encyclopedia|General encyclopedic works]], [[Yearbook|yearbooks]], [[Almanac|almanacs]], [[dictionaries]], directories
|<ref name=":5" />
|-
|040
|
|Unassigned
|
|-
|050||AN, AP ||General [[Serial (literature)|serials]] and their indexes, [[periodicals]], journals
|<ref name=":5" />
|-
|060||AM, AS, AY||[[Collections management|General organization]] and [[museology]], [[Academy|academies]] and [[learned societies]], [[Museum|museums]], collectors and [[collecting]], associations, [[Organization|organizations]]
|<ref name=":5" />
|-
|070||AN, PN, Z278–549 ||[[News media]], [[journalism]], [[publishing]], [[Newspaper|newspapers]]
|<ref name=":5" /><ref name=":16">{{Cite web |title=Library of Congress Classification Outline – Class P |url=https://www.loc.gov/catdir/cpso/lcco/lcco_p.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref name=":22" />
|-
|080||AC ||[[Quotation|Quotations]], [[Collection (publishing)|collections]], collected works, [[Serial (literature)|series]]
|<ref name=":5" />
|-
|090||Z4-115||[[Manuscript|Manuscripts]], [[rare books]], [[history of books]]
|<ref name=":22" />
|-
|'''100'''||B||[[Psychology]] and [[philosophy]], [[Philosophy of history|philosophy history]]
|<ref name=":6">{{Cite web |title=Library of Congress Classification Outline – Class B |url=https://www.loc.gov/catdir/cpso/lcco/lcco_b.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|110
|B, BD, BH
|[[Philosophy of history|Philosophy history]], [[metaphysics]], [[speculative philosophy]], [[aesthetics]]
|<ref name=":6" />
|-
|120||BD143–237||[[Epistemology]], [[speculative philosophy]]
|<ref name=":6" />
|-
|130||BF1001–1999||[[Parapsychology]], [[occult sciences]], [[astrology]]
|<ref name=":6" />
|-
|140
|B, BD
|[[Philosophical schools|Philosophical schools of thought]], [[speculative philosophy]], [[Philosophy of history|philosophy history]]
|<ref name=":6" />
|-
|150||BF1–940||[[Psychology]]
|<ref name=":6" /><ref name=":11" /><ref name=":18" />
|-
|160||BC||[[Logic]]
|<ref name=":6" />
|-
|170||BJ||[[Ethics]]
|<ref name=":6" />
|-
|180||B, BL, BQ||[[Ancient philosophy]], [[medieval philosophy]], [[Eastern philosophy]], [[Religion|religions]], [[mythology]],[[rationalism]], [[Buddhism]], [[Philosophy of history|philosophy history]] 
|<ref name=":6" />
|-
|190||B||[[Modern Western philosophy]], [[Philosophy of history|philosophy history]]
|<ref name=":6" />
|-
|'''200'''||BL||[[Religion]], [[mythology]]
|<ref name=":6" />
|-
|210||B, BL||[[Philosophy of religion]], [[theory of religion]], [[Philosophy of history|philosophy history]], religions, mythology
|<ref name=":6" />
|-
|220||BS||[[Bible|The Bible]]
|<ref name=":6" />
|-
|230||BR||[[Christianity]] and [[Christian theology]]
|<ref name=":6" />
|-
|240
|BR, BT
|Christian practice and observance, [[doctrinal theology]]
|<ref name=":6" />
|-
|250||BR, BT||Christian [[pastoral practice]] and [[Religious order|religious orders]]
|<ref name=":6" />
|-
|260||BR, BT||Church organization, [[social work]], [[worship]]
|<ref name=":6" />
|-
|270||BR, BT||Christian [[church history]]
|<ref name=":6" />
|-
|280||BR, BX||[[Christian denomination|Christian denominations]], religions
|<ref name=":6" />
|-
|290||BL, BM, BP, BQ||Other religions, [[Judaism]], [[Islam]], [[Buddhism]], [[Theosophy]], [[Bahism]]
|<ref name=":6" />
|-
|'''300'''||H, HM, HN, HQ, HS, HT||[[Social sciences]], [[sociology]], [[anthropology]], [[human ecology]], [[anthropogeography]]
|<ref name=":11">{{Cite web |title=Library of Congress Classification Outline – Class H |url=https://www.loc.gov/catdir/cpso/lcco/lcco_h.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref name=":10">{{Cite web |title=Library of Congress Classification Outline – Class G |url=https://www.loc.gov/catdir/cpso/lcco/lcco_g.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|310||HA ||[[Statistics]]
|<ref name=":11" />
|-
|320||HX, J, JA, JC, JF, JK, JL, JN, JQ, JS, JV, JX||[[Political science]], [[socialism]], [[communism]], [[anarchism]], [[political theory]], theory of the state, [[Constitutional history]], [[local government]], [[colonies]] and [[colonization]], [[emigration]] and [[immigration]], [[international law]], [[international relations]]
|<ref name=":12">{{Cite web |title=Library of Congress Classification Outline – Class J |url=https://www.loc.gov/catdir/cpso/lcco/lcco_j.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|330||HB, HC, HD, HE, HF, HG, HJ||[[Economics]], [[economics theory]], [[economics history]], [[transportation]], [[communication]], [[commerce]], [[finance]], [[public finance]], [[Environmental science|environmental sciences]]
|<ref name=":11" />
|-
|340||JX, K, KD, KE, KF, KG, KH, KJ||[[Law]], [[international law]], [[law of the United Kingdom]], [[Law of Ireland (state)|law of Ireland]], [[law of Canada]], [[law of the United States]], law of Latin America, [[Law in South America|law of South America]], [[Law in Europe|law of Europe]]
|<ref name=":13">{{Cite web |title=Library of Congress Classification Outline – Class K |url=https://www.loc.gov/catdir/cpso/lcco/lcco_k.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|350||JF, JS, U, V||[[Public administration]] and [[military science]], [[constitutional history]], [[local government]], [[naval science]]
|<ref name=":12" />
|-
|360||HN, HV ||[[Social problems]], [[social services]], [[social history]], [[social reforms]], [[social pathology]], [[criminology]]
|<ref name=":11" />
|-
|370||L||[[Education]]
|<ref name=":14">{{Cite web |title=Library of Congress Classification Outline – Class L |url=https://www.loc.gov/catdir/cpso/lcco/lcco_l.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|380||HE, HF||[[Commerce]], [[transport|communications]], and [[transport]]
|<ref name=":11" />
|-
|390||BJ, CE, GR, GT||[[Tradition|Customs]], [[etiquette]], [[folklore]], [[calendar]], [[manners]]
|<ref name=":10" />
|-
|'''400'''||P, AG||[[Language]], [[philology]], [[linguistics]], [[Dictionary|dictionaries]]
|<ref name=":16" />
|-
|410||P||[[Linguistics]], philology 
|<ref name=":16" />
|-
|420||PE||[[English language]], [[Old English Language|Old English languages]], [[English philology]]
|<ref name=":16" />
|-
|430||PD, PF||[[Germanic language]]s, [[Germanic philology]], [[West Germanic languages|West Germanic language]], West Germanic philology
|<ref name=":16" />
|-
|440||PC||[[French language]],  [[Romance philology]]
|<ref name=":16" />
|-
|450||PC||[[Italian language]], [[Romanian language]], [[Rhaeto-Romanic language|Rhaeto–Romanic language]],  Romance philology,  [[Romance languages]]
|<ref name=":16" />
|-
|460||PC||[[Spanish language]], [[Portuguese language]]
|<ref name=":16" />
|-
|470||PA, PC||[[Latin|Latin language]], [[Italic languages]], [[classical philology]], [[classical literature]]; [[modern Greek literature]], [[Byzantine literature]], [[medieval Latin literature]], modern Latin literature,  Romance philology
|<ref name=":16" />
|-
|480||PA||[[Classical Greek language]], modern Greek language, classical philology, classical literature, Byzantine literature, modern Greek literature, medieval Latin literature, modern Latin literature
|<ref name=":16" />
|-
|490||PB, PG, PH, PJ, PK, PL, PM||Other Languages: [[Celtic languages|Celtic language]], [[Celtic literature]], [[Slavic languages]], [[Slavic literature]], [[Baltic languages]] and literature, [[Albanian language]], [[Albanian literature]], [[Finno-Ugric languages|Finno-Ugarian languages]] and literature, [[Basque language]], [[Basque literature]], [[Egyptian language]] and philogy, [[Coptic language]] and philogy, [[Hamitic language]] and philogy, [[Semitic languages]],[[Semitic philology]], [[Indo-Iranian languages]], [[Iranian literature|Indo-Iranian literature]], [[East Asian languages|Eastern Asian languages]], [[East Asian literature|Eastern Asian literature]], [[Oceanic languages|Oceanian languages]], [[Oceanian literature]], [[African languages]],[[African literature|African literatures]], [[American Indian languages]], [[Artificial language|artificial languages]]
|<ref name=":16" />
|-
|'''500'''||Q||[[Science]]
|<ref name=":18" />
|-
|510||QA||[[Mathematics]], [[computer science]]
|<ref name=":18" />
|-
|520||QB||[[Astronomy]]
|<ref name=":18" />
|-
|530||QC||[[Physics]]
|<ref name=":18" />
|-
|540||QD||[[Chemistry]], [[crystallography]]
|<ref name=":18" />
|-
|550||QE, GC ||[[Earth science|Earth sciences]], [[geology]], [[oceanography]]
|<ref name=":18" /><ref name=":10" />
|-
|560||GF, GN, QE, QH||[[Fossil|Fossils]], [[prehistoric life]], [[human ecology]], [[anthropogeography]], [[anthropology]], [[geology]], [[natural history]], [[biology]]
|<ref name=":18" />
|-
|570||QH, QP, QR||[[Life sciences]], biology, natural history, [[microbiology]]
|<ref name=":18" /><ref name=":10" />
|-
|580||QK||[[Botany]]
|<ref name=":18" />
|-
|590||QL||[[Animal]]s, [[zoology]]
|<ref name=":18" />
|-
|'''600'''||T||[[Technology]] ([[applied sciences]])
|<ref name=":21">{{Cite web |title=Library of Congress Classification Outline – Class T |url=https://www.loc.gov/catdir/cpso/lcco/lcco_t.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|610||QM, R, RA, RB, RC, RD, RE, RF, RG, RJ, RK, RL, RM, RS, RT, RV, RX, RZ||[[Medicine]], [[human anatomy]], [[public health]], [[pathology]], [[internal medicine]], [[surgery]], [[ophthalmology]], [[otorhinolaryngology]], [[Gynaecology|gynecology]], [[obstetrics]], [[pediatrics]], [[dentistry]], [[dermatology]], [[therapeutics]], [[pharmacology]], [[pharmacy]], [[nursing]], [[Thomsonian medicine]], [[eclectic medicine]], [[homeopathy]], [[Systems medicine|other systems of medicine]]
|<ref name=":19">{{Cite web |title=Library of Congress Classification Outline – Class R |url=https://www.loc.gov/catdir/cpso/lcco/lcco_r.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref name=":18" />
|-
|620||TA, TC, TD, TE, TF, TG, TJ, TK, TL, TN, TR||[[Engineering]], [[hydraulic engineering]], [[environmental engineering]], [[sanitary engineering]], [[highway engineering]], [[Road|roads]] and pavement, [[railroads]], [[railway engineering]], [[mechanical engineering]], [[electrical engineering]], [[nuclear engineering]], [[Motor vehicle|motor vehicles]], [[aeronautics]], [[astronautics]], [[mining engineering]], [[metallurgy]], [[photography]]
|<ref name=":21" /><ref name=":18" /><ref name=":23">{{Cite web |title=Library of Congress Classification Outline – Class U |url=https://www.loc.gov/catdir/cpso/lcco/lcco_u.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref><ref>{{Cite web |title=Library of Congress Classification Outline – Class V |url=https://www.loc.gov/catdir/cpso/lcco/lcco_v.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|630||S, SB, SD, SF, SH, SK||[[Agriculture]], plant industry, [[Animal husbandry|animal industry]], [[Horticulture|plant culture]], [[forestry]], [[animal culture]], [[aquaculture]], [[fisheries]], [[angling]], [[hunting]]
|<ref name=":20">{{Cite web |title=Library of Congress Classification Outline – Class S |url=https://www.loc.gov/catdir/cpso/lcco/lcco_s.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|640||TT, TX||[[Home management]], [[Family|family management]], [[home economics]], [[Handicraft|handicrafts]], [[arts and crafts]]
|<ref name=":21" />
|-
|650||H, HA, HB, HC, HD, HF, HG, HM||[[Management]], [[public relations]], [[Social science|social sciences]], [[statistics]], [[economic theory]], [[demography]], [[economic history]], [[commerce]], [[finance]], [[public finance]]
|<ref name=":11" />
|-
|660||TP||[[Chemical engineering]]
|<ref name=":21" />
|-
|670||TS||[[Manufacturing]]
|<ref name=":11" />
|-
|680||TS, TT||Manufacturing specific products, [[graphic arts]]
|<ref name=":21" />
|-
|690||TH||[[Building]] and [[construction]]
|<ref name=":21" />
|-
|'''700'''||N, NX||[[Arts]], [[visual arts]]
|<ref name=":17">{{Cite web |title=Library of Congress Classification Outline – Class N |url=https://www.loc.gov/catdir/cpso/lcco/lcco_n.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|710||SB||[[Landscaping]], [[Landscape architecture|area planning]], [[Plant tissue culture|plant culture]]
|<ref name=":20" />
|-
|720||NA||[[Architecture]]
|<ref name=":17" />
|-
|730||NB, CJ||[[Sculpture]], [[Ceramic|ceramics]], [[Metalworking|metalwork]], [[numismatics]]
|<ref name=":17" />
|-
|740||NC, NK||[[Drawing]], [[decorative arts]], [[design]], [[illustration]], [[applied arts]], decoration, [[Ornament (art)|ornament]]
|<ref name=":17" />
|-
|750||ND||[[Painting]], [[drawing]], [[design]], [[illustration]], [[painting]], [[print media]]
|<ref name=":17" />
|-
|760||NC, ND, NE||[[Graphic arts]], [[printmaking]], [[Art print|prints]]
|<ref name=":17" />
|-
|770||TR||[[Photography]] and [[photographs]]
|<ref name=":21" />
|-
|780||M, ML, MT||[[Music]], [[instrumental music]], [[vocal music]], literature of music, [[music instruction]]
|<ref name=":15">{{Cite web |title=Library of Congress Classification Outline – Class M |url=https://www.loc.gov/catdir/cpso/lcco/lcco_m.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|790||GV||[[Sport|Sports]], [[Game|games]], [[entertainment]], [[recreation]], [[leisure]]
|<ref name=":16" /><ref name=":10" />
|-
|'''800'''||P, PN||[[Literature]], [[rhetoric]], [[criticism]], [[language]], [[literary history]], [[Literary collection|literary collections]], [[Theatre|theater]], [[Speech|oratory]], [[journalism]]
|<ref name=":16" />
|-
|810||PS, PZ||[[American literature]] in English, juvenile [[Belles-lettres|belles letters]]
|<ref name=":16" />
|-
|820||PR, PZ||[[English literature]], [[Old English literature]], juvenile belles letters
|<ref name=":16" />
|-
|830||PT, PZ||[[German literature]], [[Germanic literature]], juvenile belles letters
|<ref name=":16" />
|-
|840||PQ, PZ||[[French literature]],  [[Romance studies|Romance literature]], juvenile belles letters
|<ref name=":16" />
|-
|850||PQ, PZ||[[Italian literature]], [[Romanian literature]],  Romance literature, juvenile belles letters
|<ref name=":16" />
|-
|860||PQ, PZ||[[Spanish literature]], [[Portuguese literature]],  Romance literature, juvenile belles letters
|<ref name=":16" />
|-
|870||PQ, PZ||[[Latin literature]], [[Italian literature]], [[Classical philology]], [[Classical literature]], [[Byzantine literature]], [[medieval Latin literature]], modern Latin literature, juvenile belles letters
|<ref name=":16" />
|-
|880||PA, PZ||[[Greek literature|Classical Greek literature]], [[modern Greek literature]], classical philology and literature, juvenile belles letters
|<ref name=":16" />
|-
|890||PB, PG, PH, PJ, PK, PL, PZ||Other languages, [[Celtic languages]], [[Celtic literature]], [[Slavic languages]], [[Slavic literature]], [[Baltic languages]] and literature, [[Albanian languages]], [[Albanian literature]], [[Finno-Ugric languages|Finno-Ugarian languages]] and literature, [[Basque language]], [[Basque literature]], [[Egyptian language]] and philology, [[Coptic language]] and philology, [[Hamitic languages]] and philology, [[Semitic languages]], [[Semitic philology]], [[Indo-Iranian languages]], [[Iranian literature|Indo-Iranian literature]], [[East Asian languages|Eastern Asian languages]], [[East Asian literature|East Asinan literature]], [[Oceanic languages]], [[Oceanian literature]], [[African languages]], [[African literature]], juvenile belles letters
|<ref name=":16" />
|-
|'''900'''||CB, D, E, F||[[History]], [[history of civilization]], [[topography]], [[history of the United States]], [[local history]] of the United States, [[History of North America|history of North America except the U.S.]], [[history of South America]]
|<ref name=":10" /><ref name=":8" /><ref name=":7">{{Cite web |title=Library of Congress Classification Outline – Class C |url=https://www.loc.gov/catdir/cpso/lcco/lcco_c.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|910||G, GA, GB||[[Geography]], [[travel]], [[mathematical geography]], [[cartography]], [[physical geography]]
|<ref name=":10" /><ref name=":7" />
|-
|920||CD, CR, CS, CT||[[Biography]], [[genealogy]], [[diplomatics]], [[Archive|archives]], seals, [[heraldry]]
|<ref name=":7" />
|-
|930||CB, CC, CN, DA, DAW, DB, DC, DD, DE, DF, DG||[[ancient history|History of ancient world]] (to ca. 499 A.D.), [[history of civilization]], [[archaeology]], [[epigraphy]], [[inscriptions]], [[classical antiquity]], [[Ancient britain|Great Britain]], Central Europe, Austria, Lichtenstein, Hungary, Czechoslovakia, [[Ancient France|France]], Andorra, Monaco, [[Ancient Germany|Germany]], East Germany, [[History of the Mediterranean region|Mediterranean]], [[History of Ancient Greece|Greece]], [[Ancient Italy|Italy]], Malta
|<ref name=":8">{{Cite web |title=Library of Congress Classification Outline – Class D |url=https://www.loc.gov/catdir/cpso/lcco/lcco_d.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|940||DA, DAW, DB, DC, DD, DF, DG, DH, DJ, DJK, DK, DL, DP, DQ, DR||[[History of Europe]] (ca 500 A.D.), [[History of the British Isles|Great Britain]], [[History of Central Europe|Central Europe]], [[History of Austria|Austria]], [[history of Liechtenstein|Liechtenstein]], [[History of Hungary|Hungary]], [[History of Czechoslovakia|Czechoslovakia]], [[History of France|France]], [[History of Andorra|Andorra]], [[History of Monaco|Monaco]], [[History of Germany|Germany]], [[History of East Germany|East Germany]], [[History of Greece|Greece]], [[History of Italy|Italy]], [[History of Malta|Malta]], [[History of Belgium|Belgium]], [[History of Luxembourg|Luxembourg]], [[History of Holland|Holland]], [[History of Eastern Europe|Eastern Europe]], [[History of the Soviet Union|Soviet Union]], [[History of Poland|Poland]], [[history of Scandinavia|Scandinavia]], [[History of Spain|Spain]], [[History of Portugal|Portugal]], [[History of Switzerland|Switzerland]], [[History of the balkan peninsula|Balkan peninsula]]
|<ref name=":8" />
|-
|950||DS||[[History of Asia]], [[History of China|China]], [[History of Japan|Japan]], [[History of the Arabian Peninsula|Arabian Peninsula]], [[history of Saudi Arabia|Saudi Arabia]], [[History of India|India]], [[History of Iran|Iran]] ([[Persia]])
|<ref name=":8" />
|-
|960||DT||[[History of Africa]], [[History of Libya|Libya]], [[History of Tunisia|Tunisia]], [[History of Egypt|Egypt]], [[History of Sudan|Sudan]], [[History of Ethiopia|Ethiopia]] ([[Abyssinia]]), [[History of Eritrea|Eritrea]], [[History of Algeria|Algeria]], [[History of West Africa|West Africa]], [[History of Central Africa|Central Africa]], [[History of South Africa|South Africa]]
|<ref name=":8" />
|-
|970||E, F1–1392||[[History of North America]], [[History of United States|United States]], [[History of Canada|Canada]], [[History of Mexico|Mexico]] 
|<ref name=":9">{{Cite web |title=Library of Congress Classification Outline – Classes E and F |url=https://www.loc.gov/catdir/cpso/lcco/lcco_ef.pdf |access-date=August 21, 2025 |website=Library of Congress}}</ref>
|-
|980||F1401–3799||[[History of South America]], [[History of Central America|Central America]], [[History of Brazil|Brazil]], [[History of Argentina|Argentina]], [[History of Chile|Chile]], [[History of Bolivia|Bolivia]], [[History of Peru|Peru]], [[History of Venezuela|Venezuela]]
|<ref name=":9" />
|-
|990||DU||History of other regions, [[History of Oceania|Oceania]], [[History of Australia|Australia]], [[History of New Zealand|New Zealand]], [[History of Melanesia|Melanesia]], [[History of New Guinea|New Guinea]]
|<ref name=":8" />
|}

==See also==

* [[Classification]]
* [[Decimal classification]]
* [[Library catalog]]
* [[Library of Congress Subject Headings]]
* [[List of Dewey Decimal classes]]

==Further reading==

* Billy, Amber; Nelson, Elizabeth; and Uhl, Rebecca. ''Inclusive Cataloging: Histories, Context, and Reparative Approaches.'' Chicago: ALA Editions, 2024. {{ISBN|979-8-89255-566-1}}.
* Chan, Lois Mai. ''A Guide to the Library of Congress Classification, 6th ed.'' New York: [[Libraries Unlimited]], 2016. {{ISBN|978-1440844331}}.
* Chan, Lois Mai and Salaba, Athena. ''Cataloging and Classification: An Introduction''. Lanham, Maryland: [[Rowman & Littlefield Publishers]], Inc., 2016. {{ISBN|9781442232495}}.
* Merkley, Carl. "The Library of Congress, Dewey Decimal, and Universal Decimal Classification Systems are Incomplete and Unsystematic". ''[[Evidence Based Library and Information Practice (journal)|Evidence Based Library and Information Practice]]'', vol. 6, no. 4 (2011): 134–136. doi.org/10.18438/B8QK7S.
* Satija, M. P. ''The Theory and Practice of the Dewey Decimal Classification System''. Hull: [[Chandos Publishing]], 2013. {{ISBN|978-1843347385}}.
* Scott, Mona L. ''Dewey Decimal Classification: A Study Manual and Number Building Guide, 22nd edition''. New York: [[Libraries Unlimited]], 2005. {{ISBN|978-1591582106}}.
* Sroka, Marek. "Library of Congress Subject Headings, Dewey Decimal Classification and the Ambiguity of Subject Representation of Central, Eastern and South-Eastern Europe in American Knowledge Organization Systems." ''Central European and Balkan Studies'', vol. 33 (November 21, 2024): 9–16. doi.org/10.4467/2543733XssB.24.001.20025
* Weihs, Jean and Intner, Sheila S. ''Beginning Cataloging,'' ''2nd editio''n. [[Bloomsbury Publishing]], 2016. {{ISBN|9798216052197}}.

==References==
{{reflist}}

== External links ==

* [https://www.loc.gov/catdir/cpso/classwebtutorial/9dewey.html Quick Start Tutorial: LC/Dewey Correlations] (Library of Congress).
* Ross, Geoffrey. ''[https://www.library.illinois.edu/hpnl/blog/lcc/ Dewey → Library of Congress Classification]'' (History, Philosophy, and Newspaper Library, University of Illinois).

[[Category:Comparisons|Dewey and Library of Congress subject classification]]
[[Category:Library of Congress Classification| ]]
[[Category:Dewey Decimal Classification]]
[[Category:Library cataloging and classification]]