Roman Numeral Converter - Numbers to Roman & Back

A Roman numeral converter transforms Arabic numbers (1, 2, 3) into Roman numerals (I, II, III) or decodes Roman numerals back to standard digits. Use it for document formatting, clock designs, or historical references.

1. Enter input: Type a number (1–3999) or a Roman numeral string.
2. Choose direction: Select Number to Roman or Roman to Number.
3. Convert: Copy the result for documents, graphics, or code.

• Formal formatting: Add Roman numerals to chapter headings, outlines, or legal documents.
• Design projects: Generate Roman numerals for clock faces, logos, or tattoos.
• Educational: Learn or teach the Roman numeral system with instant conversion.

Use case 1: Document headings

Convert section numbers to Roman numerals for academic papers or formal reports.

Use case 2: Clock design

Generate numerals I through XII for clock face graphics.

Use case 3: Event naming

Create Roman numeral suffixes for annual events like "Conference XXIV."

Basic example

Input: 2024
Output: MMXXIV

Advanced example

Input: MCMLXXXIV
Output: 1984

Numbers above 3999

Traditional Roman numerals max out at 3999 (MMMCMXCIX). Larger numbers require extended notation.

Invalid Roman strings

Only valid combinations of I, V, X, L, C, D, M convert correctly. Random letters return errors.

• Use uppercase Roman numerals for formal contexts; lowercase for informal outlines.
• Double-check subtractive pairs (IV for 4, IX for 9) when writing by hand.
• Combine with the title case converter when formatting numbered headings.

• Generate random numbers with the random number generator.
• Format numbered lists using the sentence counter for stats.
• Convert to binary with the binary converter.

Conversion runs locally in your browser. No numbers are uploaded or stored.