Comparison Between Dewey Decimal Classification (DDC) and Library of Congress Classification (LCC)



DDC vs. LCC

Comparison Between Dewey Decimal Classification (DDC) and Library of Congress Classification (LCC)



The Dewey Decimal Classification (DDC) and the Library of Congress Classification (LCC) are two prominent systems used to organize library materials by subject, facilitating easy location and retrieval of resources on shelves. DDC was developed by Melvil Dewey in 1876 and is widely used in public, school, and small academic libraries, while LCC was created by the Library of Congress in the late 19th century and is preferred in large academic and research libraries. Both systems are hierarchical and topic-based, but they differ in structure, scope, and application. 


Structure and Main Features

  • DDC:
    • Numeric system with 10 main classes ranging from 000 to 900.
    • Each main class is divided into 10 divisions, and each division into 10 sections, using decimals for further subdivisions.
    • Notation includes a three-digit number for the subject, followed by a cutter number for the author or title.
    • Designed for flexibility in small to medium collections; can be expanded or abbreviated.
    • Total of 99 second-level classes (two-digit subdivisions).
  • LCC:
    • Alpha-numeric system with 21 main classes denoted by letters (A–Z, skipping I, O, W, X, Y for future expansion).
    • Each class has subclasses (additional letters), followed by numeric codes for topics, cutter numbers for authors, and often a publication year.
    • More granular, with thousands of subclasses, suited for very large or specialized collections (e.g., over 500,000 items).
    • Developed specifically for the Library of Congress’s vast holdings, allowing for precise categorization. 

Similarities

  • Both classify materials by subject to group related items together.
  • Hierarchical organization allows for broadening or narrowing searches.
  • Used globally for shelving and cataloging, with call numbers printed on book spines.
  • Aim to make library navigation intuitive for users. 

Differences

  • Scope and Usage: DDC is simpler and more universal, ideal for general audiences in public libraries, but may lack depth for extensive collections. LCC is more detailed and customizable, better for academic environments with specialized topics, but can be complex to learn. 
  • Notation: DDC uses purely numbers and decimals (e.g., expandable like 123.456), while LCC combines letters and numbers (e.g., less intuitive but more capacity for subclasses).
  • Number of Classes: DDC has 10 main classes; LCC has 21.
  • Advantages of DDC: Easy to understand, consistent across libraries, good for broad categories.
  • Disadvantages of DDC: Can become cumbersome with long decimal strings in large libraries; some biases in original design (e.g., Western-centric).
  • Advantages of LCC: Highly specific, scalable for growth, no length limits on notations.
  • Disadvantages of LCC: Steeper learning curve, not as standardized outside academic settings. 

Examples of Classification

Here are some specific examples showing how the same or similar subjects are classified in each system, based on standard mappings: 

  • General Works/Computer Science:
    • DDC: 000 (Computer science, information, general works).
    • LCC: A (General works), QA (Mathematics/Computer science).
    • Example Book: “Introduction to Algorithms” might be DDC 005.1 (Data structures), LCC QA76.9.A43 (Algorithms).
  • Philosophy and Psychology:
    • DDC: 100 (Philosophy & psychology).
    • LCC: B (Philosophy, Psychology, Religion).
    • Example Book: “The Republic” by Plato – DDC 184 (Platonic philosophy), LCC B358 (Plato’s works).
  • Religion:
    • DDC: 200 (Religion).
    • LCC: BL (Religions, Mythology).
    • Example Book: “The Bible” – DDC 220 (Bible), LCC BS (Bible).
  • Social Sciences:
    • DDC: 300 (Social sciences).
    • LCC: H (Social sciences).
    • Example Book: “The Wealth of Nations” by Adam Smith – DDC 330.153 (Economics), LCC HB161 (Economic theory).
  • Language:
    • DDC: 400 (Language).
    • LCC: P (Philology, Linguistics).
    • Example Book: “English Grammar” – DDC 425 (English grammar), LCC PE1112 (English language grammar).
  • Science:
    • DDC: 500 (Pure sciences).
    • LCC: Q (Science).
    • Example Book: “A Brief History of Time” by Stephen Hawking – DDC 523.1 (Cosmology), LCC QB981 (Cosmology).
  • Technology:
    • DDC: 600 (Technology).
    • LCC: T (Technology).
    • Example Book: “The Art of Electronics” – DDC 621.381 (Electronics), LCC TK7815 (Electronics).
  • Arts:
    • DDC: 700 (Arts & recreation).
    • LCC: N (Fine arts).
    • Example Book: “History of Art” – DDC 709 (Art history), LCC N5300 (Art history).
  • Literature:
    • DDC: 800 (Literature).
    • LCC: PN (Literature general).
    • Example Book: “To Kill a Mockingbird” by Harper Lee – DDC 813.54 (American fiction), LCC PS3562.E353 (Lee’s works).
  • History and Geography:
    • DDC: 900 (History & geography).
    • LCC: D (History general and Old World).
    • Example Book: “Guns, Germs, and Steel” by Jared Diamond – DDC 303.4 (Social processes), LCC CB (History of civilization).



Comparison (DDC vs LCC)

The following table compares the organization of resources by the Dewey Decimal and Library of Congress classification systems. It includes all 99 second-level (two-digit) Dewey Decimal classes (excluding 040), and all second-level (two-digit) Library of Congress classes.

Dewey Decimal Classification (DDC)Library of Congress Classification (LCC)Description
000A, AZ, QA, TA, Z4–659Computer science, knowledge, and general works; history of scholarship and learning
010AI, Z1001–8999Bibliography, indexes
020Z4–1000.5Library and information sciences
030AE, AG, AYGeneral encyclopedic works, yearbooks, almanacs, dictionaries, directories
040Unassigned
050AN, APGeneral serials and their indexes, periodicals, journals
060AM, AS, AYGeneral organization and museology, academies and learned societies, museums, collectors and collecting, associations, organizations
070AN, PN, Z278–549News media, journalism, publishing, newspapers
880ACQuotations, collections, collected works, series
090Z4-115Manuscripts, rare books, history of books
100BPsychology and philosophy, philosophy history
110B, BD, BHPhilosophy history, metaphysics, speculative philosophy, aesthetics
120BD143–237Epistemology, speculative philosophy
130BF1001–1999Parapsychology, occult sciences, astrology
140B, BDPhilosophical schools of thought, speculative philosophy, philosophy history
150BF1–940Psychology
160BCLogic
170BJEthics
180B, BL, BQAncient philosophy, medieval philosophy, Eastern philosophy, religions, mythology, rationalism, Buddhism, philosophy history
190BModern Western philosophy, philosophy history
200BLReligion, mythology
210B, BLPhilosophy of religion, theory of religion, philosophy history, religions, mythology
220BSThe Bible
230BRChristianity and Christian theology
240BR, BTChristian practice and observance, doctrinal theology
250BR, BTChristian pastoral practice and religious orders
260BR, BTChurch organization, social work, worship
270BR, BTChristian church history
280BR, BXChristian denominations, religions
290BL, BM, BP, BQOther religions, Judaism, Islam, Buddhism, Theosophy, Baháʼísm
300H, HM, HN, HQ, HS, HTSocial sciences, sociology, anthropology, human ecology, anthropogeography
310HAStatistics
320HX, J, JA, JC, JF, JK, JL, JN, JQ, JS, JV, JXPolitical science, socialism, communism, anarchism, political theory, theory of the state, Constitutional history, local government, colonies and colonization, emigration and immigration, international law, international relations
330HB, HC, HD, HE, HF, HG, HJEconomics, economics theory, economics history, transportation, communication, commerce, finance, public finance, environmental sciences
340JX, K, KD, KE, KF, KG, KH, KJLaw, international law, law of the United Kingdom, law of Ireland, law of Canada, law of the United States, law of Latin America, law of South America, law of Europe
350JF, JS, U, VPublic administration and military science, constitutional history, local government, naval science
360HN, HVSocial problems, social services, social history, social reforms, social pathology, criminology
370LEducation
380HE, HFCommerce, communications, and transport
390BJ, CE, GR, GTCustoms, etiquette, folklore, calendar, manners
400P, AGLanguage, philology, linguistics, dictionaries
410PLinguistics, philology
420PEEnglish language, Old English languages, English philology
430PD, PFGermanic languages, Germanic philology, West Germanic language, West Germanic philology
440PCFrench language, Romance philology
450PCItalian language, Romanian language, Rhaeto–Romanic language, Romance philology, Romance languages
460PCSpanish language, Portuguese language
470PA, PCLatin language, Italic languages, classical philology, classical literature; modern Greek literature, Byzantine literature, medieval Latin literature, modern Latin literature, Romance philology
480PAClassical Greek language, modern Greek language, classical philology, classical literature, Byzantine literature, modern Greek literature, medieval Latin literature, modern Latin literature
490PB, PG, PH, PJ, PK, PL, PMOther Languages: Celtic language, Celtic literature, Slavic languages, Slavic literature, Baltic languages and literature, Albanian language, Albanian literature, 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, Indo-Iranian literature, Eastern Asian languages, Eastern Asian literature, Oceanian languages, Oceanian literature, African languages, African literatures, American Indian languages, artificial languages
500QScience
510QAMathematics, computer science
520QBAstronomy
530QCPhysics
540QDChemistry, crystallography
550QE, GCEarth sciences, geology, oceanography
560GF, GN, QE, QHFossils, prehistoric life, human ecology, anthropogeography, anthropology, geology, natural history, biology
570QH, QP, QRLife sciences, biology, natural history, microbiology
580QKBotany
590QLAnimals, zoology
600TTechnology (applied sciences)
610QM, R, RA, RB, RC, RD, RE, RF, RG, RJ, RK, RL, RM, RS, RT, RV, RX, RZMedicine, human anatomy, public health, pathology, internal medicine, surgery, ophthalmology, otorhinolaryngology, gynecology, obstetrics, pediatrics, dentistry, dermatology, therapeutics, pharmacology, pharmacy, nursing, Thomsonian medicine, eclectic medicine, homeopathy, other systems of medicine
620TA, TC, TD, TE, TF, TG, TJ, TK, TL, TN, TREngineering, hydraulic engineering, environmental engineering, sanitary engineering, highway engineering, roads and pavement, railroads, railway engineering, mechanical engineering, electrical engineering, nuclear engineering, motor vehicles, aeronautics, astronautics, mining engineering, metallurgy, photography
630S, SB, SD, SF, SH, SKAgriculture, plant industry, animal industry, plant culture, forestry, animal culture, aquaculture, fisheries, angling, hunting
640TT, TXHome management, family management, home economics, handicrafts, arts and crafts
650H, HA, HB, HC, HD, HF, HG, HMManagement, public relations, social sciences, statistics, economic theory, demography, economic history, commerce, finance, public finance
660TPChemical engineering
670TSManufacturing
680TS, TTManufacturing specific products, graphic arts
690THBuilding and construction
700N, NXArts, visual arts
710SBLandscaping, area planning, plant culture
720NAArchitecture
730NB, CJSculpture, ceramics, metalwork, numismatics
740NC, NKDrawing, decorative arts, design, illustration, applied arts, decoration, ornament
750NDPainting, drawing, design, illustration, painting, print media
760NC, ND, NEGraphic arts, printmaking, prints
770TRPhotography and photographs
780M, ML, MTMusic, instrumental music, vocal music, literature of music, music instruction
790GVSports, games, entertainment, recreation, leisure
800P, PNLiterature, rhetoric, criticism, language, literary history, literary collections, theater, oratory, journalism
810PS, PZAmerican literature in English, juvenile belles letters
820PR, PZEnglish literature, Old English literature, juvenile belles letters
830PT, PZGerman literature, Germanic literature, juvenile belles letters
840PQ, PZFrench literature, Romance literature, juvenile belles letters
850PQ, PZItalian literature, Romanian literature, Romance literature, juvenile belles letters
860PQ, PZSpanish literature, Portuguese literature, Romance literature, juvenile belles letters
870PQ, PZLatin literature, Italian literature, Classical philology, Classical literature, Byzantine literature, medieval Latin literature, modern Latin literature, juvenile belles letters
880PA, PZClassical Greek literature, modern Greek literature, classical philology and literature, juvenile belles letters
890PB, PG, PH, PJ, PK, PL, PZOther languages, Celtic languages, Celtic literature, Slavic languages, Slavic literature, Baltic languages and literature, Albanian languages, Albanian literature, 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, Indo-Iranian literature, Eastern Asian languages, East Asinan literature, Oceanic languages, Oceanian literature, African languages, African literature, juvenile belles letters
900CB, D, E, FHistory, history of civilization, topography, history of the United States, local history of the United States, history of North America except the U.S., history of South America
910G, GA, GBGeography, travel, mathematical geography, cartography, physical geography
920CD, CR, CS, CTBiography, genealogy, diplomatics, archives, seals, heraldry
930CB, CC, CN, DA, DAW, DB, DC, DD, DE, DF, DGHistory of ancient world (to ca. 499 A.D.), history of civilization, archaeology, epigraphy, inscriptions, classical antiquity, Great Britain, Central Europe, Austria, Lichtenstein, Hungary, Czechoslovakia, France, Andorra, Monaco, Germany, East Germany, Mediterranean, Greece, Italy, Malta
940DA, DAW, DB, DC, DD, DF, DG, DH, DJ, DJK, DK, DL, DP, DQ, DRHistory of Europe (ca 500 A.D.), Great Britain, Central Europe, Austria, Liechtenstein, Hungary, Czechoslovakia, France, Andorra, Monaco, Germany, East Germany, Greece, Italy, Malta, Belgium, Luxembourg, Holland, Eastern Europe, Soviet Union, Poland, Scandinavia, Spain, Portugal, Switzerland, Balkan peninsula
950DSHistory of Asia, China, Japan, Arabian Peninsula, Saudi Arabia, India, Iran (Persia)
960DTHistory of Africa, Libya, Tunisia, Egypt, Sudan, Ethiopia (Abyssinia), Eritrea, Algeria, West Africa, Central Africa, South Africa
970E, F1–1392History of North America, United States, Canada, Mexico
980F1401–3799History of South America, Central America, Brazil, Argentina, Chile, Bolivia, Peru, Venezuela
990DUHistory of other regions, Oceania, Australia, New Zealand, Melanesia, New Guinea






CITATION INFORMATION

Article Title: Comparison Between Dewey Decimal Classification (DDC) and Library of Congress Classification (LCC)

Author: Salman Haider

Website Name: Librarianship Studies & Information Technology

URL: https://www.librarianshipstudies.com/2026/01/comparison-between-dewey-decimal.html