How to Convert Roman Numerals to Arabic Numbers and Vice Versa

Roman numerals are an ancient system of counting used by the Romans and are still used in many parts of the world today. While Arabic numbers (1, 2, 3, etc.) are the standard in modern times, Roman numerals still pop up in clocks, movie titles, and even in the names of monarchs. In this guide, we’ll show you how to convert Roman numerals to Arabic numbers and vice versa using simple steps.

Whether you’re using a Roman Numerals converter online or doing it by hand, understanding the basics of this system will make it easier to make the switch. Roman numerals use letters from the Latin alphabet— I, V, X, L, C, D, and M— to represent numbers. For example, I = 1, V = 5, and X = 10. Knowing the value of these letters helps when converting them into Arabic numbers.

Converting Roman Numerals to Arabic Numbers

The Roman numeral system is based on adding or subtracting values depending on the placement of the numeral. Here’s how you can convert them:

• Add Values: If a smaller numeral is before a larger numeral, you subtract it (e.g., IV = 4). If it’s after, you add it (e.g., VI = 6).
  
• Examples:
  
  • XVI = 16 (10 + 5 + 1)
    IX = 9 (10 – 1)
    

Converting Arabic Numbers to Roman Numerals

Converting Arabic numbers to Roman numerals follows a set of simple rules:

1. Start with the largest Roman numeral (M for 1000) and subtract it from the Arabic number.
   
2. Continue down with smaller numerals, following the Roman numeral chart.
   

For example, 39 in Arabic becomes XXXIX (30 + 9).

Tips for Quick Conversion

If you’re looking to convert Roman numerals to Arabic numbers or vice versa quickly, this website gives you Roman numerals converters that are available online. These tools are super helpful, especially when you’re dealing with complex numbers.