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⌀Diameter signU+2300Ready to copy
47 diameter signs and look-alikes. Tap any value to copy it.
47 diameter signs and look-alikes. A character and its name both copy the character. A code copies the code.
Character
Name
Code point
Alt code
Option keys
HTML
LaTeX
U+2300. The sign a technical drawing puts before or after a number to say it is a diameter, as in ⌀ 55 mm. In Unicode since version 1.1 (1993), in the Miscellaneous Technical block. It has no Alt code, no Option key and no named HTML entity: write ⌀ in HTML.
U+00D8. A letter, not a diameter sign: Danish, Norwegian, Faroese and Southern Sámi use it. Unicode's alias: o slash. It has the keys ⌀ lacks: Alt+0216 on a number pad, Option+Shift+O on a U.S. layout, Ø in HTML and \O in LaTeX text.
U+00F8. The small letter. Unicode's note: Danish, Norwegian, Faroese, IPA. Alt+0248 on a number pad, Option+O on a U.S. layout, ø in HTML and \o in LaTeX text.
U+2205. The set that has no elements. Unicode's alias: null set. The sign is credited to the Bourbaki group, André Weil in particular, in 1939, with the letter Ø as its model. ∅ in HTML, \varnothing in LaTeX with the amssymb package, and plain LaTeX has \emptyset.
Made of U+2300, U+0031 and U+0030. The diameter sign in front of a number, the way a drawing marks a hole of 10 mm diameter. Swap in your own number.
U+2298. A maths operator, a division slash inside a circle, and one of the characters the diameter sign is confused with. ⊘ in HTML and \oslash in LaTeX.
Made of U+0053 and U+2300. The letter S before the diameter sign. On a drawing it marks the diameter of a sphere, beside SR for a spherical radius.
U+2334. Unicode files it under Drafting symbols. A counterbore is a flat-bottomed hole that widens another hole, so that a screw head can sit flush with the surface or below it.
U+2335. The drafting sign for a countersink, a conical hole that lets the head of a countersunk screw sit flush with the surface or below it.
U+21A7. Unicode's alias: depth symbol. On a drawing the depth sign defines the depth of a feature. ↧ in HTML.
U+03A6. A Greek capital letter, a circle crossed by a vertical bar, often mistaken for the null sign. Alt+232 on a number pad, Φ in HTML and \Phi in LaTeX.
U+25A1. One of the most used dimensioning signs: it marks a square feature, as ⌀ marks a round one. □ in HTML. Its LaTeX macro needs the amssymb package.
U+23E4. Straightness among the geometric tolerance signs of an engineering drawing. Added in version 5.0 (2006). Unicode's alias is direct current symbol form one, so the character serves two trades.
U+23E5. Flatness among the geometric tolerance signs of an engineering drawing. Added in version 5.0 (2006). The HTML entity ▱ does not type it: that name belongs to ▱, White parallelogram.
U+25CB. Circularity among the geometric tolerance signs of an engineering drawing. Alt+9 on a number pad and ○ in HTML.
U+232D. Cylindricity among the geometric tolerance signs of an engineering drawing. Unicode files it under Drafting symbols. ⌭ in HTML.
U+2312. Profile of a line among the geometric tolerance signs of an engineering drawing. Unicode's alias: position of any line. ⌒ in HTML.
U+2313. Profile of a surface among the geometric tolerance signs of an engineering drawing. Unicode's alias: position of a surface. ⌓ in HTML.
U+27C2. Perpendicularity among the geometric tolerance signs of an engineering drawing. Unicode's alias: orthogonal to. Added in version 4.1 (2005). \perp in LaTeX.
U+2220. Angularity among the geometric tolerance signs of an engineering drawing. ∠ in HTML and \angle in LaTeX.
U+2225. Parallelism among the geometric tolerance signs of an engineering drawing. ∥ in HTML and \parallel in LaTeX.
U+232F. Symmetry among the geometric tolerance signs of an engineering drawing. The 2018 revision of the standard eliminated symmetry and concentricity.
U+2316. Position among the geometric tolerance signs of an engineering drawing. Unicode's alias: true position. ⌖ in HTML.
U+25CE. Concentricity among the geometric tolerance signs of an engineering drawing. It is the other sign that the 2018 revision eliminated.
U+2197. Circular run-out among the geometric tolerance signs of an engineering drawing. ↗ in HTML and \nearrow in LaTeX. It has the Emoji property, so an app may draw it in colour.
U+2330. Total run-out among the geometric tolerance signs of an engineering drawing. Unicode files it under Drafting symbols.
U+24C2. The modifier for maximum material condition in a feature control frame, the box that holds a geometric tolerance. It has the Emoji property, so an app may draw it in colour.
U+24C1. The modifier for least material condition in a feature control frame.
U+01FE. Ø with an acute accent. Unicode gives its make-up as Ø plus U+0301 and files it under Phonetic and historic letters.
U+01FF. The small letter of the pair: ø plus U+0301.
U+A74A. An O with a long stroke laid over it, one of the Medievalist additions of version 5.1 (2008).
U+A74B. The small letter of the pair, which Unicode cross-references to ø.
U+1D13. An ø turned on its side, in the Phonetic Extensions block since version 4.0 (2003).
U+03C6. The ordinary Greek small phi. Unicode notes that mathematics prefers the loopy glyph, to set it apart from ϕ. Alt+237 on a number pad, φ in HTML and \varphi in LaTeX.
U+03D5. Unicode notes its use as a technical symbol drawn with a stroke. ϕ in HTML, and in LaTeX it is this one that \phi prints.
U+0278. The phonetic alphabet's phi. Unicode's note: voiceless bilabial fricative.
U+0424. A Cyrillic capital, a circle crossed by a vertical bar, corresponding to f. Ф in HTML.
U+0444. The small letter of the pair. ф in HTML.
U+2349. A sign of the APL programming language, a circle with a backslash through it. Unicode cross-references it to ⦰.
U+233D. APL again, a circle with an upright stile through it. ⌽ in HTML.
U+29B8. A reverse solidus inside a circle, filed under Circle symbols. Added in version 3.2 (2002).
U+1F6AB. The emoji list calls it prohibited. The general prohibition sign is a red circle holding a line from upper left to lower right. Added in version 6.0 (2010).
U+2D41. A letter of Tifinagh, the script of the Berber languages, corresponding to h. One of the characters the diameter sign is confused with. Added in version 4.1 (2005).
Made of U+0030 and U+FE00. The digit zero plus the variation selector U+FE00. Unicode's name for the pair: short diagonal stroke form. The slash of a slashed zero usually stays inside the oval, unlike the stroke of Ø, ∅ and ⌀. Where a font has no such form, a plain 0 shows.
U+2BD0. Unicode cross-references it to ⌖, Position indicator, and files it under Miscellaneous symbols. Added in version 7.0 (2014).
U+AB3E. A blackletter o with a stroke. Unicode files it under Letters for German dialectology. Added in version 7.0 (2014).
U+1F6C7. Not in the emoji list. Unicode cross-references it to 🚫. Added in version 7.0 (2014).
The diameter symbol is ⌀, Diameter sign, U+2300. The 47 rows add the letter Ø and the empty set ∅ that it is confused with, the signs a drawing puts beside it, and labelled look-alikes.
Read the full guide
The signs that go with it
On a drawing ⌀ goes before the number, as in ⌀10, and S⌀ marks a sphere. ⌴ is a counterbore, ⌵ a countersink and ↧ the depth. The group Diameter and drawing signs adds the fourteen geometric tolerance signs, from ⏤ straightness to ⌰ total run-out, and the modifiers Ⓜ and Ⓛ.
▱ in HTML types ▱, a parallelogram, not ⏥ Flatness. No entity names ⌀ either, so write ⌀ or ⌀.
Slashed zero is 0 plus U+FE00. Where a font has no such form, the plain zero shows.
Questions and answers
How do I type the diameter symbol on a keyboard?
⌀ has no Alt code and no Option key, so copy it. With a Compose key, press Compose, d, i. The letter Ø has keys: Alt+0216 on a Windows number pad, or Option+Shift+O on a Mac with the U.S. layout.
What is the difference between ⌀, Ø and ∅?
⌀ is U+2300, Diameter sign, for technical drawings. Ø is U+00D8, a letter of Danish, Norwegian, Faroese and Southern Sámi. ∅ is U+2205, Empty set, which the Bourbaki group introduced in 1939 with Ø as its model. A search treats them as three characters.
What is the diameter symbol in HTML and LaTeX?
HTML has no name for ⌀, so write ⌀ or ⌀. In LaTeX, \diameter needs the wasysym package. Ø and \O print the letter Ø, and ∅ and \varnothing print ∅, the empty set.
All 47 diameter signs and look-alikes
Start here 11
⊘Circled division slashU+2298. A maths operator, a division slash inside a circle, and one of the characters the diameter sign is confused with. ⊘ in HTML and \oslash in LaTeX.
⌴CounterboreU+2334. Unicode files it under Drafting symbols. A counterbore is a flat-bottomed hole that widens another hole, so that a screw head can sit flush with the surface or below it.
⌵CountersinkU+2335. The drafting sign for a countersink, a conical hole that lets the head of a countersunk screw sit flush with the surface or below it.
⌀10Diameter of 10Made of U+2300, U+0031 and U+0030. The diameter sign in front of a number, the way a drawing marks a hole of 10 mm diameter. Swap in your own number.
⌀Diameter signU+2300. The sign a technical drawing puts before or after a number to say it is a diameter, as in ⌀ 55 mm. In Unicode since version 1.1 (1993), in the Miscellaneous Technical block. It has no Alt code, no Option key and no named HTML entity: write ⌀ in HTML.
↧Downwards arrow from barU+21A7. Unicode's alias: depth symbol. On a drawing the depth sign defines the depth of a feature. ↧ in HTML.
Show all 47 diameter signs and look-alikes (41 more)
Start here, continued
∅Empty setU+2205. The set that has no elements. Unicode's alias: null set. The sign is credited to the Bourbaki group, André Weil in particular, in 1939, with the letter Ø as its model. ∅ in HTML, \varnothing in LaTeX with the amssymb package, and plain LaTeX has \emptyset.
ΦGreek capital letter phiU+03A6. A Greek capital letter, a circle crossed by a vertical bar, often mistaken for the null sign. Alt+232 on a number pad, Φ in HTML and \Phi in LaTeX.
ØLatin capital letter O with strokeU+00D8. A letter, not a diameter sign: Danish, Norwegian, Faroese and Southern Sámi use it. Unicode's alias: o slash. It has the keys ⌀ lacks: Alt+0216 on a number pad, Option+Shift+O on a U.S. layout, Ø in HTML and \O in LaTeX text.
øLatin small letter o with strokeU+00F8. The small letter. Unicode's note: Danish, Norwegian, Faroese, IPA. Alt+0248 on a number pad, Option+O on a U.S. layout, ø in HTML and \o in LaTeX text.
S⌀Spherical diameterMade of U+0053 and U+2300. The letter S before the diameter sign. On a drawing it marks the diameter of a sphere, beside SR for a spherical radius.
Diameter and drawing signs 18
∠AngleU+2220. Angularity among the geometric tolerance signs of an engineering drawing. ∠ in HTML and \angle in LaTeX.
⌒ArcU+2312. Profile of a line among the geometric tolerance signs of an engineering drawing. Unicode's alias: position of any line. ⌒ in HTML.
◎BullseyeU+25CE. Concentricity among the geometric tolerance signs of an engineering drawing. It is the other sign that the 2018 revision eliminated.
ⓁCircled Latin capital letter LU+24C1. The modifier for least material condition in a feature control frame.
ⓂCircled Latin capital letter MU+24C2. The modifier for maximum material condition in a feature control frame, the box that holds a geometric tolerance. It has the Emoji property, so an app may draw it in colour.
⌭CylindricityU+232D. Cylindricity among the geometric tolerance signs of an engineering drawing. Unicode files it under Drafting symbols. ⌭ in HTML.
⏥FlatnessU+23E5. Flatness among the geometric tolerance signs of an engineering drawing. Added in version 5.0 (2006). The HTML entity ▱ does not type it: that name belongs to ▱, White parallelogram.
↗North east arrowU+2197. Circular run-out among the geometric tolerance signs of an engineering drawing. ↗ in HTML and \nearrow in LaTeX. It has the Emoji property, so an app may draw it in colour.
∥Parallel toU+2225. Parallelism among the geometric tolerance signs of an engineering drawing. ∥ in HTML and \parallel in LaTeX.
⟂PerpendicularU+27C2. Perpendicularity among the geometric tolerance signs of an engineering drawing. Unicode's alias: orthogonal to. Added in version 4.1 (2005). \perp in LaTeX.
⌖Position indicatorU+2316. Position among the geometric tolerance signs of an engineering drawing. Unicode's alias: true position. ⌖ in HTML.
⌓SegmentU+2313. Profile of a surface among the geometric tolerance signs of an engineering drawing. Unicode's alias: position of a surface. ⌓ in HTML.
⯐Square position indicatorU+2BD0. Unicode cross-references it to ⌖, Position indicator, and files it under Miscellaneous symbols. Added in version 7.0 (2014).
⏤StraightnessU+23E4. Straightness among the geometric tolerance signs of an engineering drawing. Added in version 5.0 (2006). Unicode's alias is direct current symbol form one, so the character serves two trades.
⌯SymmetryU+232F. Symmetry among the geometric tolerance signs of an engineering drawing. The 2018 revision of the standard eliminated symmetry and concentricity.
⌰Total runoutU+2330. Total run-out among the geometric tolerance signs of an engineering drawing. Unicode files it under Drafting symbols.
○White circleU+25CB. Circularity among the geometric tolerance signs of an engineering drawing. Alt+9 on a number pad and ○ in HTML.
□White squareU+25A1. One of the most used dimensioning signs: it marks a square feature, as ⌀ marks a round one. □ in HTML. Its LaTeX macro needs the amssymb package.
The letter Ø 6
ꝊLatin capital letter O with long stroke overlayU+A74A. An O with a long stroke laid over it, one of the Medievalist additions of version 5.1 (2008).
ǾLatin capital letter O with stroke and acuteU+01FE. Ø with an acute accent. Unicode gives its make-up as Ø plus U+0301 and files it under Phonetic and historic letters.
ꬾLatin small letter blackletter o with strokeU+AB3E. A blackletter o with a stroke. Unicode files it under Letters for German dialectology. Added in version 7.0 (2014).
ꝋLatin small letter o with long stroke overlayU+A74B. The small letter of the pair, which Unicode cross-references to ø.
ǿLatin small letter o with stroke and acuteU+01FF. The small letter of the pair: ø plus U+0301.
ᴓLatin small letter sideways o with strokeU+1D13. An ø turned on its side, in the Phonetic Extensions block since version 4.0 (2003).
Look-alikes 12
⍉APL functional symbol circle backslashU+2349. A sign of the APL programming language, a circle with a backslash through it. Unicode cross-references it to ⦰.
⌽APL functional symbol circle stileU+233D. APL again, a circle with an upright stile through it. ⌽ in HTML.
⦸Circled reverse solidusU+29B8. A reverse solidus inside a circle, filed under Circle symbols. Added in version 3.2 (2002).
ФCyrillic capital letter efU+0424. A Cyrillic capital, a circle crossed by a vertical bar, corresponding to f. Ф in HTML.
фCyrillic small letter efU+0444. The small letter of the pair. ф in HTML.
ϕGreek phi symbolU+03D5. Unicode notes its use as a technical symbol drawn with a stroke. ϕ in HTML, and in LaTeX it is this one that \phi prints.
φGreek small letter phiU+03C6. The ordinary Greek small phi. Unicode notes that mathematics prefers the loopy glyph, to set it apart from ϕ. Alt+237 on a number pad, φ in HTML and \varphi in LaTeX.
ɸLatin small letter phiU+0278. The phonetic alphabet's phi. Unicode's note: voiceless bilabial fricative.
🚫No entry signU+1F6AB. The emoji list calls it prohibited. The general prohibition sign is a red circle holding a line from upper left to lower right. Added in version 6.0 (2010).
🛇Prohibited signU+1F6C7. Not in the emoji list. Unicode cross-references it to 🚫. Added in version 7.0 (2014).
0︀Slashed zeroMade of U+0030 and U+FE00. The digit zero plus the variation selector U+FE00. Unicode's name for the pair: short diagonal stroke form. The slash of a slashed zero usually stays inside the oval, unlike the stroke of Ø, ∅ and ⌀. Where a font has no such form, a plain 0 shows.
ⵁTifinagh letter berber academy yahU+2D41. A letter of Tifinagh, the script of the Berber languages, corresponding to h. One of the characters the diameter sign is confused with. Added in version 4.1 (2005).