𝝓 Mathematical Bold Italic Phi Symbol

What 𝝓 means

It marks a distinct phi symbol; the formula defines its role.

The bold italic phi symbol is a distinct math character, not a universal name for one quantity. An author might define it as a vector, angle, parameter or another value; follow the surrounding formula.

In LaTeX, \boldsymbol{\varphi} requests a bold looped phi; the math font controls the exact glyph.

Why are there two phi shapes?

They are two forms of the Greek letter phi.

Unicode associates 𝝓 with ϕ, the looped Greek phi, and 𝝋 with the straight-stem φ. Mathematical alphabets preserve style distinctions in plain text because a formula can use them to distinguish symbols.

Which meanings can phi have?

Phi has different jobs in different formulas.

Carl Friedrich Gauss used φ for the totient function in 1801. It counts positive integers below n that share no factor greater than 1 with n.

The same Greek letter also names the golden ratio in geometry. Those are uses of phi, not meanings built into its bold italic style.

In math notation, bold italic marks a distinct symbol; its role still depends on the author's definitions.

NFKC normalization can reduce this to φ, removing its styled and variant identity.

What it means when someone sends it to you

3 readings

The totient function: it counts positive integers below n that share no factor greater than 1 with n.

Don't confuse it with

4

𝝋

Mathematical Bold Italic Small Phi

𝝓 versus 𝝋: this is the looped form, while 𝝋 follows straight-stem φ; fonts can make them look closer.

∅

Empty Set

∅ is the empty-set sign, a circle with a slash. 𝝓 is a bold italic Greek phi used as a variable. The two are often swapped.

⌀

Diameter Sign

⌀ is the diameter sign on technical drawings. 𝝓 is a bold italic Greek phi.

Ø

Latin Capital Letter O With Stroke

Ø is a Danish and Norwegian letter, an O with a slash. 𝝓 is a Greek phi in math bold italic.

Related characters

3

ϕ

Greek Phi Symbol

Unicode associates 𝝓 with this looped Greek phi form; the bold italic character preserves a mathematical style distinction.

φ

Greek Small Letter Phi

The ordinary Greek small phi. ϕ is its separately encoded variant, which 𝝓 sets in bold italic.

Φ

Greek Capital Letter Phi

The Greek capital phi, the uppercase counterpart of phi.

Combination ideas

3

The golden ratio, about 1.618.

Power factor: cosine of the phase angle.

A quarter-cycle phase shift between two waves.

Questions people ask

1

Why does 𝝓 show as a box on some devices?

Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.

More like this

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How to type or find 𝝓

Search it as: bold phi · bold italic phi · varphi · phi symbol · phi unicode · math phi
Shows up in: Anything that takes text · its shape is whatever your font draws

Windows (Word)

⎇Alt+XType 1D753, then AltX to get 𝝓.

Windows

⊞Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win .).

macOS

⌃Control+⌘Command+␣SpaceOpen the character viewer and search “mathematical bold italic phi symbol”.

Linux

⎈Ctrl+⇧Shift+UType 1d753, then Enter or Space.

HTML

𝝓

CSS

\1D753

LaTeX

To typeset 𝝓 in LaTeX, use \boldsymbol{\varphi}; it requests bold looped phi, with the exact glyph set by your math font.

HTML

Write 𝝓 in HTML source for this exact character.

Families this belongs to

2

Letters1,265 symbols

µ ʹ ـ ℀℁ℂ ℃℄℅℆ℇ ℈

Fancy letters996 symbols

𝐀 𝐁 𝐂 𝐃 𝐄 𝐅 𝐆 𝐇 𝐈 𝐉 𝐊 𝐋

Mathematical Bold Italic Phi Symbol