Roman Numeral Converter

Convert Arabic numerals to Roman numerals, or Roman numerals to Arabic. Convert multiple lines at once — all processing happens inside your browser, so your values are never sent externally.

How to use

  1. Enter the values to convert, one per line, in the input box.
  2. Choose the conversion direction (number → Roman or Roman → number).
  3. Click "Convert", then copy the value in the result box with "Copy result".

Frequently asked questions

What is the maximum I can convert?

It converts 1 to 3999 following standard Roman numeral rules. Values out of range or in the wrong format are shown as a question mark.

Can I convert several at once?

Yes. Enter one per line and each line is converted in order.

Are the values I enter sent to a server?

No. All processing happens inside your browser, and the values you enter are never sent to any external server.