Roman numerals to number converter
Paste a Roman numeral from a book, clock or building to learn its value. The tool also checks that it is written correctly.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter roman numeral.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Symbol values are added left to right, and a symbol is subtracted when it comes before a larger one: MCMXCIV = 1000 + (1000 − 100) + (100 − 10) + (5 − 1) = 1994.
Example
Inputs: Roman numeral = MCMXCIV. Result: Number: 1,994.
MCMXCIV
MCMXCIV
Limits and caveats
- Only the standard form is accepted, so IIII, IC and VV are rejected even though some old inscriptions use them.
- The maximum is 3999; numerals with an overline are not read here.
Questions about this tool
Does letter case matter?
No. Lowercase input such as mcmxciv is converted to uppercase before reading.
Why is IIII rejected when some clocks show it?
The standard form of 4 is IV. IIII is a decorative clock-face tradition, not the general rule.
What does XLII mean?
It means 42: XL is 40 and II is 2.