Mathematical Bold Italic Capital I 𝑰

Visual Description: This is a bold italic capital I. The strokes are thick and the letter slants to the right. It feels tall and clean, with simple lines. It belongs to the mathematical alphanumeric symbols family. In formulas and notes, it signals a special role.

Meaning & Usage: In formulas, it can stand for a variable or a named object. The bold italic style helps separate it from ordinary letters. In math writing, symbols like this I show a special role in notation. Editors and calculators provide a quick button or palette to insert it. This makes building expressions faster and reduces ambiguity.

Historical Background: The idea of bold and italic math symbols grew with printed math texts. Designers added distinct formats to keep meaning clear in dense equations. Different fonts and software libraries expanded the set of symbols. The goal was to help readers track variables, operators, and identifiers. There is no single origin; the style evolved with printing and digital typography.

Practical Use: In digital tools, you can insert it from a symbol picker or keyboard shortcut. In calculators or editors, it appears as a quick option for building expressions. UI controls for operations or comparisons let you swap, highlight, or align symbols with other terms. Use it to keep notation clear when labeling objects or comparing values.

See our category page for related symbols.

Look‑alikes: l (U+6C).

Need styled alternatives? Try the Fancy Text tool.