Symbols for zero

The modern numerical digit 0 is usually written as a circle, an ellipse or a rounded square or rectangle.

Glyphs

In most modern typefaces, the height of the 0 character is the same as the other digits. However, in typefaces with text figures, the character is often shorter (x-height).

Traditionally, many print typefaces made the capital letter O more rounded than the narrower, elliptical digit 0. Typewriters originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into prominence on modern character displays.

The digit 0 with a dot in the centre seems to have originated as an option on IBM 3270 displays. Its appearance has continued with Taligent's command line typeface Andalé Mono.

An alternative, the slashed zero (looking similar to the letter O except for the slash), was primarily used in hand-written coding sheets before transcription to punched cards or tape, and is also used in old-style ASCII graphic sets descended from the default typewheel on the Teletype Model 33 ASR. This form is similar to the symbol ∅ {\displaystyle \emptyset } representing the empty set (U+2205∅EMPTY SET), as well as to the letter ⟨Ø⟩ (U+00D8ØLATIN CAPITAL LETTER O WITH STROKE) used in several Scandinavian languages. Some Burroughs/Unisys equipment displays a digit 0 with a reversed slash.

The opposing convention that has the letter O with a slash and the digit 0 without was advocated by SHARE, a prominent IBM user group, and recommended by IBM for writing FORTRAN programs, and by a few other early mainframe makers; this is even more problematic for Scandinavians because it means two of their letters collide. Others advocated the opposite convention, including IBM for writing Algol programs. Another convention used on some early line printers left digit 0 unornamented but added a tail or hook to the capital O so that it resembled an inverted letter ⟨Q⟩ (Q) or cursive capital letter-O (O {\displaystyle {\mathcal {O}}}, U+1D4AA𝒪MATHEMATICAL SCRIPT CAPITAL O).

Some computer fonts made one of the capital-O more rounded and the digit-0 more angular (closer to a rectangle). The TI-99/4A computer has a more angular capital O and a more rounded digit 0, whereas others made the choice the other way around.

German license plate with slit zeros

The typeface used on most European vehicle registration plates distinguishes the two symbols partially in this manner (having a more rectangular or wider shape for the capital O than the digit 0), but in several countries a further distinction is made by slitting open the digit 0 on the upper right side (as in German plates using the fälschungserschwerende Schrift, "forgery-impeding typeface").

Sometimes the digit 0 is used either exclusively, or not at all, to avoid confusion altogether. For example, confirmation numbers[bettersourceneeded] used by Southwest Airlines use only the capital letters O and I instead of the digits 0 and 1, while Canadian postal codes use only the digits 1 and 0 and never the capital letters O and I, although letters and numbers always alternate.

Other

Usual appearance of zero on seven-segment displays
Unusual smaller appearance of zero on seven-segment displays
International maritime signal flag for 0

On the seven-segment displays of calculators, watches, and household appliances, 0 is usually shown with six line segments, though on some historical calculator models it was shown with four line segments.

The international maritime signal flag has five plus signs in an X arrangement.

Zero symbols in Unicode

U+00300 DIGIT ZERO
U+0660٠ ARABIC-INDIC DIGIT ZERO
U+06DF۟ ARABIC SMALL HIGH ROUNDED ZERO
U+06E0۠ ARABIC SMALL HIGH UPRIGHT RECTANGULAR ZERO
U+06F0۰ EXTENDED ARABIC-INDIC DIGIT ZERO
U+07C0߀ NKO DIGIT ZERO
U+0966० DEVANAGARI DIGIT ZERO
U+09E6০ BENGALI DIGIT ZERO
U+0A66੦ GURMUKHI DIGIT ZERO
U+0AE6૦ GUJARATI DIGIT ZERO
U+0B66୦ ORIYA DIGIT ZERO
U+0BE6௦ TAMIL DIGIT ZERO
U+0C66౦ TELUGU DIGIT ZERO
U+0C78౸ TELUGU FRACTION DIGIT ZERO FOR ODD POWERS OF FOUR
U+0CE6೦ KANNADA DIGIT ZERO
U+0D66൦ MALAYALAM DIGIT ZERO
U+0DE6෦ SINHALA LITH DIGIT ZERO
U+0E50๐ THAI DIGIT ZERO
U+0ED0໐ LAO DIGIT ZERO
U+0F20༠ TIBETAN DIGIT ZERO
U+0F33༳ TIBETAN DIGIT HALF ZERO
U+1040၀ MYANMAR DIGIT ZERO
U+1090႐ MYANMAR SHAN DIGIT ZERO
U+17E0០ KHMER DIGIT ZERO
U+1810᠐ MONGOLIAN DIGIT ZERO
U+1946᥆ LIMBU DIGIT ZERO
U+19D0᧐ NEW TAI LUE DIGIT ZERO
U+1A80᪀ TAI THAM HORA DIGIT ZERO
U+1A90᪐ TAI THAM THAM DIGIT ZERO
U+1B50᭐ BALINESE DIGIT ZERO
U+1BB0᮰ SUNDANESE DIGIT ZERO
U+1C40᱀ LEPCHA DIGIT ZERO
U+1C50᱐ OL CHIKI DIGIT ZERO
U+2070⁰ SUPERSCRIPT ZERO
U+2080₀ SUBSCRIPT ZERO
U+2189↉ VULGAR FRACTION ZERO THIRDS
U+24EA⓪ CIRCLED DIGIT ZERO
U+24FF⓿ NEGATIVE CIRCLED DIGIT ZERO
U+3007〇 IDEOGRAPHIC NUMBER ZERO
U+3358㍘ IDEOGRAPHIC TELEGRAPH SYMBOL FOR HOUR ZERO
U+A620꘠ VAI DIGIT ZERO
U+A8D0꣐ SAURASHTRA DIGIT ZERO
U+A8E0꣠ COMBINING DEVANAGARI DIGIT ZERO
U+A900꤀ KAYAH LI DIGIT ZERO
U+A9D0꧐ JAVANESE DIGIT ZERO
U+A9F0꧰ MYANMAR TAI LAING DIGIT ZERO
U+AA50꩐ CHAM DIGIT ZERO
U+ABF0꯰ MEETEI MAYEK DIGIT ZERO
U+FF10０ FULLWIDTH DIGIT ZERO
U+1018A𐆊 GREEK ZERO SIGN
U+104A0𐒠 OSMANYA DIGIT ZERO
U+10D30𐴰 HANIFI ROHINGYA DIGIT ZERO
U+11066𑁦 BRAHMI DIGIT ZERO
U+110F0𑃰 SORA SOMPENG DIGIT ZERO
U+11136𑄶 CHAKMA DIGIT ZERO
U+111D0𑇐 SHARADA DIGIT ZERO
U+112F0𑋰 KHUDAWADI DIGIT ZERO
U+11366𑍦 COMBINING GRANTHA DIGIT ZERO
U+11450𑑐 NEWA DIGIT ZERO
U+114D0𑓐 TIRHUTA DIGIT ZERO
U+11650𑙐 MODI DIGIT ZERO
U+116C0𑛀 TAKRI DIGIT ZERO
U+11730𑜰 AHOM DIGIT ZERO
U+118E0𑣠 WARANG CITI DIGIT ZERO
U+11950𑥐 DIVES AKURU DIGIT ZERO
U+11C50𑱐 BHAIKSUKI DIGIT ZERO
U+11D50𑵐 MASARAM GONDI DIGIT ZERO
U+11DA0𑶠 GUNJALA GONDI DIGIT ZERO
U+16A60𖩠 MRO DIGIT ZERO
U+16B50𖭐 PAHAWH HMONG DIGIT ZERO
U+16E80𖺀 MEDEFAIDRIN DIGIT ZERO
U+1D2E0𝋠 MAYAN NUMERAL ZERO
U+1D7CE𝟎 MATHEMATICAL BOLD DIGIT ZERO
U+1D7D8𝟘 MATHEMATICAL DOUBLE-STRUCK DIGIT ZERO
U+1D7E2𝟢 MATHEMATICAL SANS-SERIF DIGIT ZERO
U+1D7EC𝟬 MATHEMATICAL SANS-SERIF BOLD DIGIT ZERO
U+1D7F6𝟶 MATHEMATICAL MONOSPACE DIGIT ZERO
U+1E140𞅀 NYIAKENG PUACHUE HMONG DIGIT ZERO
U+1E2F0𞋰 WANCHO DIGIT ZERO
U+1E950𞥐 ADLAM DIGIT ZERO
U+1F100🄀 DIGIT ZERO FULL STOP
U+1F101🄁 DIGIT ZERO COMMA
U+1F10B🄋 DINGBAT CIRCLED SANS-SERIF DIGIT ZERO
U+1F10C🄌 DINGBAT NEGATIVE CIRCLED SANS-SERIF DIGIT ZERO
U+1F10D🄍 CIRCLED ZERO WITH SLASH
U+1FBF0🯰 SEGMENTED DIGIT ZERO
U+E0030 TAG DIGIT ZERO

Symbols for zero

Glyphs

Other

Zero symbols in Unicode

See also