The Dewey Decimal Classification System is used by libraries to organize items in their collections by subject. Main subjects are given a three-digit number: 200, 300, etc., and then further broken down into sub-categories: 220, 230, 240, etc. Subdivisions of the sub-categories are shown by numbers after a decimal point: 220.550, 350.90, etc.
Following is a list of the subjects and some of the subdivisions used in the Dewey Decimal System. Click on a main subject for its sub-categories:
500 Natural Sciences & Mathematics
600 Technology (Applied Sciences)
010 Bibliography
020 Library and Information Sciences
030 General Encyclopedic Works
040 Not assigned
050 General Serial Publications
060 General Organizations & Museology
070 News Media, Journalism, Publishing
080 General Collections
090 Manuscripts & Rare Books
110 Metaphysics
120 Epistemology, causation, humankind
130 Paranormal Phenomena
140 Specific Philosophical Schools
150 Psychology
160 Logic
170 Ethics (Moral Philosophy)
180 Ancient, Medieval, Oriental Philosophy
190 Modern Western Philosophy
210 Philosophy & Theory of Religion
220 Bible
230 Christian Theology
240 Christian Moral & Devotional Theology
250 Christian Orders & Local Church
260 Social & Ecclesiastical Theology
270 History of Christianity & Christian Church
280 Christian Denominations & Sects
290 Comparative Religion & Other Religion
310 Collections of General Statistics
320 Political Science
330 Economics
340 Law
350 Public Administration & Military Science
360 Social Problems & Services
370 Education
380 Commerce, Communication, Transportation
390 Customs, Etiquette, Folklore
410 Linguistics
420 English & Old English
430 Germanic Languages German
440 Romance Languages French
450 Italian, Romanian, Rhaeto-Romanic
460 Spanish & Portuguese Languages
470 Italic Languages Latin
480 Hellenic Languages Classical Greek
490 Other Languages
510 Mathematics
520 Astronomy & Allied Sciences
530 Physics
540 Chemistry & Allied Sciences
550 Earth Sciences
560 Paleontology Paleozoology
570 Life Sciences Biology
580 Plants
590 Animals
610 Medical Sciences Medicine
620 Engineering & Allied Operations
630 Agriculture & Related Technology
640 Home Economics & Family Living
650 Management & Auxiliary Services
660 Chemical Engineering
670 Manufacturing
680 Manufacture for Specific Uses
690 Buildings
710 Civic & Landscape Art
720 Architecture
730 Plastic Arts Sculpture
740 Drawing & Decorative Arts
750 Painting and Paintings
760 Graphic Arts Printmaking
770 Photography & Photographs
780 Music
790 Recreational & Performing Arts
810 American Literature in English
820 English & Old English Literatures
830 Literatures of Germanic Languages
840 Literatures of Romance Languages
850 Italian, Romanian, Phaeto-Romanic
860 Spanish & Portuguese Literatures
870 Italic Literatures Latin
880 Hellenic Literature Classical Greek
890 Literatures of Other Languages
910 Geography & Travel
920 Biography, Genealogy, Insignia
930 History of Ancient World to ca. 499
940 General History of Europe
950 General History of Asia
960 General History of Africa
970 General History of North America
980 General History of South America
990 General History of Other Areas
