How to Convert a Number to Roman Numerals

Roman numerals are part of the counting and numbering system devised by the Romans. The Roman system was gradually replaced by the base-10 Arabic numeral system that we use today. The Arabic system is ideal for scientific and mathematical calculations, while the Roman system is rather cumbersome for doing complex mathematics. Today, we use Roman numerals primarily for stylistic and decorative effects.

The first step to convert a number to Roman numerals is to learn the chart at the left. In the Roman numeral system, the basic units are the letters I, V, X, L, C, D, and M, which represent 1, 5, 10, 50, 100, 500, and 1000 respectively. To represent the numbers 5000, 10000, 50000, 100000, 500000, and 1000000, use the letters V, X, L, C, D, and M. The bar over to top multiplies the unit by 1000.

Next, separate the digits of the decimal number into 1's, 10's, 100's, etc. For example, if you are converting the number 75493, you must separately convert the 3, 90, 400, 5000, and 70000. Using the chart, we get

3 = III
90 = XC
400 = CD
5000 = V
70000 = LXX

Finally, put string the five pieces together to generate the Roman numeral representation of 75493: LXXVCDXCIII.

You can use the chart to convert more numbers, or use the Roman numeral conversion calculator above.

Enter either a number in either decimal or Roman form, and the calculator will convert it to the other form. It will even convert Roman numerals that are entered incorrectly, for example, it will convert XXXX to 40. Currently, the converter only handles decimal numbers up to 4999.

© Had2Know 2010