Degree symbol

The degree symbol ° is a typographical symbol that is used, among other things, to represent degrees of arc (e.g. in geographic coordinate systems), hours (in the medical field), degrees of temperature, alcohol proof, or diminished quality in musical harmony.[1] The symbol consists of a small raised circle, historically a zero glyph.

The degree symbol ° redirects here. It is not to be confused with the superscript lower-case o, o; the masculine ordinal indicator, º; the ring diacritic, ˚; or the symbol denoting either a diminished triad or diminished seventh chord in music, o. For other meanings, see Degree (disambiguation).
°
Degree symbol
In UnicodeU+00B0 ° DEGREE SIGN (HTML ° · °)
Related
See alsoU+2103 ℃ DEGREE CELSIUS
U+2109 ℉ DEGREE FAHRENHEIT
Different from
Different fromU+00BA º MASCULINE ORDINAL INDICATOR

History

The first known recorded modern use of the degree symbol in mathematics is from 1657[2] where the usage seems to show that the symbol is a small raised zero, to match the prime symbol notation of sexagesimal subdivisions of degree such as minute ′, second ″, and third ‴, which originate as small raised Roman numerals.

Typography

In the case of degrees of angular arc, the degree symbol follows the number without any intervening space, e.g. 30°. The addition of minute and second of arc follows the degree units, with intervening spaces (optionally, non-breaking space) between the sexagesimal degree subdivisions but no spaces between the numbers and units, for example 30° 12′ 5″.

In the case of degrees of temperature, three scientific and engineering standards bodies (the International Bureau of Weights and Measures, the International Organization for Standardization and the U.S. Government Printing Office) prescribe printing temperatures with a space between the number and the degree symbol, e.g. 10 °C.[3][4] However, in many works with professional typesetting, including scientific works published by the University of Chicago Press or Oxford University Press, the degree symbol is printed with no spaces between the number, the symbol, and the Latin letters "C" or "F" representing Celsius or Fahrenheit, respectively, e.g. 10°C.[5][6] This is also the practice of the University Corporation for Atmospheric Research, which operates the National Center for Atmospheric Research.[7]

Use of the degree symbol to refer to temperatures measured in kelvins (symbol: K) was abolished in 1967 by the 13th General Conference on Weights and Measures (CGPM). Therefore, the triple point of water, for instance, is written simply as 273.16 K. The name of the SI unit of temperature is now "kelvin", in lower case, and no longer "degrees Kelvin".

In photography, the symbol is used to denote logarithmic film speed grades. In this usage, it follows the number without spacing as in 21° DIN, 5° ASA or ISO 100/21°.

Encoding

The degree sign is included in Unicode as U+00B0 ° DEGREE SIGN (HTML ° · °).

For use with Chinese characters there are also code points for U+2103 ℃ DEGREE CELSIUS (HTML ℃) and U+2109 ℉ DEGREE FAHRENHEIT (HTML ℉).

The degree sign was missing from the basic 7-bit ASCII set of 1963, but in 1987 the ISO/IEC 8859 standard introduced it at position 0xB0 (176 decimal) in all variants except Part 5 (Cyrillic), 6 (Arabic), 7 (Greek) and 11 (Thai). In 1991 the Unicode standard incorporated all of the ISO/IEC 8859 code points, including the degree sign (at U+00B0)..

The Windows Code Page 1252 was also an extension of ISO/IEC 8859-1 (Part 1 or Latin-1) standard, so it had the degree sign at the same code point, 0xB0. The code point in the older DOS Code Page 437 was 0xF8 (248 decimal); therefore, the Alt code used to enter the symbol directly from the keyboard is Alt+248.

Lookalikes

Other characters with similar appearance but different meanings include:

  • U+00BA º MASCULINE ORDINAL INDICATOR (HTML º · º) (indicator used in Italian, Spanish and Portuguese that follows a numeral denoting that it is an ordinal number, rather than a cardinal number; varies with the font and sometimes underlined)
  • U+1D52 ᵒ MODIFIER LETTER SMALL O (HTML ᵒ) (superscript letter o)
  • U+02DA ˚ RING ABOVE (HTML ˚) (standalone)
    • U+030A ◌̊ COMBINING RING ABOVE (HTML ̊) (applied to a letter)
    • U+0325 ◌̥ COMBINING RING BELOW (HTML ̥) (applied to a letter)
    • U+0366 ◌ͦ COMBINING LATIN SMALL LETTER O (HTML ͦ) (applied to a letter)
  • U+309C ゜ KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK (HTML ゜) (standalone)
  • U+18DE ᣞ CANADIAN SYLLABICS FINAL SMALL RING (HTML ᣞ) (stand alone, typically representing either ⟨w⟩ or ⟨y⟩)
    • (precomposed characters containing this mark also exists)
  • U+2070 ⁰ SUPERSCRIPT ZERO (HTML ⁰)
  • U+2218 ∘ RING OPERATOR (HTML ∘)
  • U+29B5 ⦵ CIRCLE WITH HORIZONTAL BAR (HTML ⦵) (used in superscripted form, ⦵, to mean standard state (chemistry))
  • U+1BC85 𛲅 DUPLOYAN AFFIX HIGH CIRCLE (HTML 𛲅)
    • U+1BC95 𛲕 DUPLOYAN AFFIX LOW CIRCLE (HTML 𛲕)
  • U+26AC ⚬ MEDIUM SMALL WHITE CIRCLE (HTML ⚬)

Keyboard entry

Some computer keyboard layouts, such as the QWERTY layout as used in Italy, the QWERTZ layout as used in Germany, Austria and Switzerland, and the AZERTY layout as used in France and Belgium, have the degree symbol available directly on a key. But the common keyboard layouts in English-speaking countries do not include the degree sign, which then has to be input some other way. The method of inputting depends on the operating system being used.

On the Colemak keyboard layout (Windows/Mac), one can press AltGr+\ followed by D to insert a degree sign. On Linux, one can press AltGr+K twice to insert a degree sign.

Desktop OS

With Microsoft Windows, there are several ways to make the degree symbol:

  • One can type Alt+248 or Alt+0176
    Note: "0176" is different from "176"; Alt+176 produces the light shade (░) character.
    Note: The NumLock must be set first; on full size keyboards, the numeric keypad must be used; on laptops without a numerical keypad, the virtual numeric keypad must be used (often requiring that the Fn key be held down as the numeric sequence is typed).
  • The Character Map tool also may be used to obtain a graphical menu of symbols.
  • The US-International English keyboard layout creates the degree symbol with AltGr+⇧ Shift+;

In the classic Mac OS and macOS operating systems, the degree symbol can be entered by typing ⌥ Opt+⇧ Shift+8. One can also use the Mac OS character palette,[8] which is available in many programs by selecting Special Characters from the Edit Menu, or from the 'Input Menu' (flag) icon on the menu bar (enabled in the International section of the System Preferences).[9]

In Linux operating systems such as Ubuntu, this symbol may be entered via the Compose key followed by o, o. Some keyboard layouts display this symbol upon pressing AltGr+⇧ Shift+0 (once or twice, depending on specific keyboard layout), and, in programs created by GTK+, one can enter Unicode characters in any text entry field by first pressing Ctrl+⇧ Shift+U+Unicode code point, regardless of keyboard layout. For the degree symbol, this is done by entering Ctrl+⇧ Shift+U B0 (where the last key is the number zero) followed by a space.

For Chrome OS, use the Unicode entry method Ctrl+⇧ Shift+U then 00B0 then space or return; with the UK extended layout, use AltGr+⇧ Shift+0.

Mobile OS

In iOS, the degree symbol is accessed by pressing and holding 0 and dragging a finger to the degree symbol. This procedure is the same as entering diacritics on other characters.

In Android, switch to numbers ?123 then symbols =\<. The degrees symbol is found on the second row.

Software-specific

In Microsoft Office and similar programs, there is often also an Insert menu with an Insert Symbol or Symbol command that brings up a graphical palette of symbols to insert, including the degree symbol. As with the CharMap app, the table is arranged in unicode order. An easier way is to use Alt+176 or B0 then Alt+X.

In LaTeX, the packages gensymb and textcomp provide the commands degree and \textdegree, respectively. In the absence of these packages one can write the degree symbol as ^{\circ} in math mode. In other words, it is written as the empty circle glyph circ as a superscript.

In AutoCAD it is available as a shortcut string %%d.

See also

References
  1. "Chord Symbols". Retrieved 2013-12-16.
  2. Cajori, Florian (1993) [1928-1929], A History of Mathematical Notations, Dover Publications, ISBN 0-486-67766-4 |page=216
  3. The International System of Units (PDF) (8th ed.), Bureau International des Poids et Mesures, 2006
  4. Style Manual (PDF) (30th ed.), United States Government Printing Office, 2008
  5. 9.16 Abbreviations and symbols, Chicago Manual of Style (15th ed.), University of Chicago, 2010
  6. 10.52 Miscellaneous technical abbreviations, Chicago Manual of Style (15th ed.), University of Chicago, 2010
  7. UCAR, UCAR Communications Style Guide, retrieved 2007-09-01
  8. "How to use emoji, accents and symbols on your Mac". apple.com. January 29, 2020. Retrieved 2 March 2020.
  9. "(unknown title)". apple.com.
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