Mathematical Sans-Serif Bold Capital O 𝗢

Visual Description: The symbol is a bold, geometric capital O. It has a uniform stroke width and no serifs. The curves are smooth and symmetrical, resembling a thick circle. In sans-serif math fonts, it reads clearly at small sizes and on screens. The shape emphasizes stability and neutrality.

Meaning & Usage: This bold O functions as a symbol in formulas and labeled objects. It can represent a variable, a set name, or a placeholder in equations. In calculators and quick UI controls, bold shapes help differentiate operations or comparisons at a glance.

Historical Background: It belongs to a family of Mathematical Alphanumeric Symbols designed to maintain consistency across math text. The sans-serif bold form was created to be legible on screens, slides, and printed pages. It is used to separate styling from meaning, helping readers distinguish symbols in dense formulas.

Practical Use: Use this O when you want a modern, high-contrast look in math and data labels. It reads well in headers and equations. In software, designers pair it with other bold sans letters for quick UI controls for operations or comparisons, keeping interfaces tidy and readable.

See our category page for related symbols.

Look‑alikes: O (U+4F).

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