Roman Numerals Calculator

Enter either a whole numeric value (between 1 and 3999) or a set of roman numerals.


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Converting roman numerals - symbols list

Featured below is a list of roman numerals and their numeric value.

Roman numerals
Symbol Value Symbol Value

A history of roman numerals

Roman numerals were the standard system of numbering used by the Romans in ancient Rome. Used primarily for counting, they were adapted from the Etruscan numerals system. The original system of numerals used in the classical era was altered slightly in the Middle Ages, resulting in the numeral system that we use today where letters represent values as numerals.

Some of the common uses of roman numerals in everyday life include use in clock faces, chapter numbering and copyrighting in books, and numbered lists. Sometimes dates are given in Roman numerals for the dating of movies and television programmes. Also, some sporting events, such as the Olympics, the Superbowl and Wrestling events use them.

Interesting fact: If you take one of each individual roman numeral and add them together, the total comes to 1666.

Roman numerals explained

With roman numerals it's not just important to note each numeral itself, but also the order in which they appear. For example, when a smaller number appears infront of a larger number it means that the smaller number should be deducted from the larger one. If the smaller number appears after it, it gets added.

An example: IX means 9 (10-1), where as XI means 11 (10+1).

There are, of course, rules to bear in mind.

How to convert roman numerals - example

Roman numerals on building in Washington

The building in the photograph above is located in Washington D.C and bears the roman numerals MCMXXII in reference to the fact that it was built in that year (A.D meaning anno Domini, or 'in the year of the Lord'). Our question is, what year do the roman numerals MCMXXII represent?

  1. Moving from left to right, we start with the numeral M. M represents 1000.
  2. The next two numerals are CM. C is 100 and M, as we already know, is 1000. As the C appears before the M, we deduct it from the M. Therefore, 1000 - 100 = 900.
  3. The remaining numerals go in order. We know that X is 10 and I is 1. So, we have 10+10+1+1.
  4. Time to add it all together. 1000+900+10+10+1+1 = 1922.

This building therefore appears to have been established in 1922.

To learn more about roman numerals, where they came from and how they work, see the article all about roman numerals.

Roman numerals charts

The fabulous folks at have created some great roman numerals cheat sheets for quick reference of this ancient numbers system. So, do head over there and download them if you want some further conversion practice.

The roman numerals calculator script on this page was adapted from a script created by Steven H Gibbs.