How to convert Roman numerals to a number
- Type the Roman numeral, in upper or lower case.
- Read the number it stands for.
- If it is rejected, read the reason and correct it.
About this tool
Type a Roman numeral and read its value. The check is strict: IIII, VX and similar forms are not standard, and the page tells you why instead of guessing a value. Lower case works too. Numbers run from 1 to 3999, with an overline option for thousands beyond that.
Common questions
Why is IIII rejected?
A letter can repeat at most three times in a row. 4 is written IV.
Why is VX not valid?
Only I, X and C can be written before a larger letter to subtract. V, L and D never are, so 5 is just V.
How is MCMXCIV read?
M is 1000, CM is 900, XC is 90 and IV is 4. Together they make 1994.
Is it free to use?
Yes. There's no sign-up, and you can use it as often as you like.
Is my text uploaded anywhere?
No. This tool runs inside your browser, so what you enter stays on your device.
Do I need to install anything?
No. It works in your browser on a computer or a phone.