Roman Numeral Converter

Convert an integer (1–3999) to Roman numerals, or decode a Roman numeral back to a number.

100% freeNo sign-upRuns in your browserNo upload · data stays private

📖 Read the full Roman Numeral Converter guide — how it works, examples & FAQ →

How to use this tool

  1. Type a number (1–3999) or a Roman numeral.
  2. Pick the direction.
  3. Copy the result.

Example

2026 → MMXXVI

Why it's private

This tool runs entirely in your browser using JavaScript. Whatever you paste is processed on your own device — it is never uploaded to a server, logged, or stored. Built by Calabi, which also strips AI metadata and C2PA signals from images and video.

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