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Roman numerals

Roman numerals are read from left to right, as you add or subtract the value of each symbol.

If a value is lower than the following value, it will be subtracted. Otherwise it will be added.

For example, we want to conver the Roman numeral MCMLIV to an Arabic number:

M = 1000 must be added, because the following letter C =100 is lower.
C = 100 must be subtracted because the following letter M =1000 is greater.
M = 1000 must be added, because the following letter L = 50 is lower.
L = 50 must be added, because the following letter I =1 is lower.
I = 1 must be subtracted, because the following letter V = 5 is greater.
V = 5 must be added, because there are no more symbols left.

We can now calculate the number:
1000 - 100 + 1000 + 50 - 1 + 5 = 1954

Convert Roman numerals to Arabic numbers

Please enter a Roman numeral between I (=1) and MMMCMXCIX (=3.999).

Roman numeral: