Convert Number to Roman Numerals

About Roman Numerals

As the name implies, Roman Numerals were a method of representing numbers dating back to the Roman Empire which began in 27 BC. It is based on 7 characters used to denote numbers: I, V, X, L, C, D, and M. These, in turn, are combined to form other numbers, with a set of fairly simple rules defining how to calculate the total value of the group.

Stand-alone, each of the 7 Roman Numerals, has a value, as shown in the chart below. If the Numeral has a bar over it, the number is multiplied by 1000.

In general, when calculating a Roman Numeral's aggregate value (ie. what all numerals combined represent), you look at the value to the left of the numeral you are evaluating. If it is less than the numeral, the value to the left is subtracted; otherwise it is added.

Some numerals can be repeated up to 3 times: I, X, C, and M; The others, V, L, and D can not be repeated, in succession. So, for example VIII is 8, but you would not construct VIIII for 9 because there are 4 I's, exceeding the rule of 3. To convert 9 to a Roman Numeral, we'd use the IX construct. Since I (number 1) is to the left of X (number 10), and its value is less than X, we'd subtract 1 from 10, yielding 9.

Are Roman Numerals Used Today?

Everywhere! While we calculate numbers in base 10 today, using the arabic numberals 0 through 9, Roman Numerals are still actively used (and seen) today. It's common that watches and grandfather clocks and other time pieces use Roman Numerals to designate the hours 1 through 12 (I - XII). Book chapters often use Roman Numerals. Other common places Roman Numerals are found are on buildings, particularly above the front door to designate when built, and on monuments and tombstones.

Several sporting events use Roman Numerals to designate the number of times the event has occurred (eg. the Superbowl and Olympics). And Roman Numerals typically are used at the end of a movie, in the copyright notice. Roman Numerals are also seen in tattoos, and in jewelry, where the value has symbolic meaning, such as a significant date. And, of course, a man's name is often followed by a Roman Numeral suffix to indicate he has a father (or uncle or other relative) with the same number. Car maker Henry Ford had a grandson Henry Ford II, and a great-great grandson Henry III.

This calculator takes a base 10 number and converts it to Roman Numeral. If you want to translate a Roman Numeral to a modern number, use our Roman Numeral Translator.