HeroTools / Text & Code
Local · Private · Free

Roman Numeral Converter

Convert numbers to Roman numerals and back — both directions, live, on your device. Handles 1 to 3,999,999.

Enter a whole number from 1 to 3,999,999.
Result appears here
Letters I V X L C D M. Use an overline value? Wrap thousands like (V) for 5,000.
Result appears here

The seven symbols

I
1
V
5
X
10
L
50
C
100
D
500
M
1,000

Subtractive pairs (IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900) keep numerals short. Standard numerals only reach 3,999 (MMMCMXCIX). For larger values, Roman scribes drew an overline (vinculum) over a numeral to multiply it by 1,000 — so an overlined V is 5,000 and an overlined X is 10,000. This tool shows the overline above, and accepts (V) parenthesis notation when you type, since overlines are hard to enter on a keyboard.

About Roman Numeral Converter

Roman Numeral Converter is a free, private text & code tool that runs entirely in your web browser. Convert numbers to Roman numerals and back (1–3,999,999). Because everything happens locally on your device, your files and data are never uploaded to a server, there is no sign-up or installation required, and it keeps working offline. It is handy for roman numerals, convert, number, latin. Like every HeroTool by Digital Heroes, Roman Numeral Converter is 100% free with no limits.

How to use Roman Numeral Converter

  1. Open Roman Numeral Converter — it runs entirely in your browser, with no signup.
  2. Paste or type your text or code into the editor.
  3. Adjust the options to match exactly what you need.
  4. Copy or download your result — it is free, and your data stays on your device.

Frequently asked questions

Is Roman Numeral Converter free?

Yes — Roman Numeral Converter is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Roman Numeral Converter runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. HeroTools is a Progressive Web App — once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Roman Numeral Converter do?

Convert numbers to Roman numerals and back (1–3,999,999).

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