Converters

Roman Numeral Converter

Convert numbers 1–3999 to Roman numerals and back, with validation.

Converter

Convert Roman numerals

Local only

Number or numeral

Everything stays in your browser

Your text is processed on your device — nothing is uploaded to a server.

Standard Roman numerals go up to 3999 (MMMCMXCIX). Incorrect forms such as IIII or VX are rejected rather than guessed.

Good to know

How do I use it?

Paste or type into the box and press “Number → Roman”. Then copy or download the result.

What should I know?

Standard Roman numerals go up to 3999 (MMMCMXCIX). Incorrect forms such as IIII or VX are rejected rather than guessed.

Is my text uploaded?

No. It is processed in your browser and never sent to a server. No account is needed.