When Should You Use Roman Numerals?

English has a long history. It’s in the family of Indo-European languages and is specifically a West Germanic language originally spoken by people who left Roman rule. We use the Latin alphabet for our writing system, but we don’t use its numeral system, Roman numerals. The base-10 numbering system we do use (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and onward) is also called the Hindu-Arabic numeral system. This is what is used for math, science, finance, and most calculations in the English-speaking world and across much of the globe. However, there are still uses for Roman numerals.

The differences between Hindu-Arabic and Roman numerals go beyond just how they look. The former are counted one by one: 1, 2, 3, 4, 5, etc. Roman numerals grow in stages:

I → 1

V → 5

X → 10

L → 50

C → 100

D → 500

M → 1000

To represent the values in between these main figures, Roman numerals use an additive or subtractive model. To translate the Roman numerals into their Hindu-Arabic counterparts, we need to do some simple math. When two Roman numerals of equal or greater value are placed sequentially, the value is added together. So VI is 5+1, which becomes 6, and XX is 10+10, which becomes 20. If the smaller numeral comes before the larger, subtract the smaller from the larger. IV is 5-1, which is 4, and XIX is 10+(10-1), which is 19. Only three of the same numeral are allowed to stay together, so instead of XXXX, XL represents 40.

After the fall of the Roman Empire in the fifth century, Roman numerals stayed strong for a few centuries. The first major documentation of the Hindu-Arabic numeral system in a math text was the Italian mathematician Fibonacci’s book Liber abaci (Book of the Abacus) in 1202. The Hindu-Arabic system was influential in developing algebra, and it began to take over in Europe. However, Roman numerals remained popular for more ceremonial uses, such as numbering important figures, including the pope of the Catholic Church and royalty. For example, Shakespeare’s historical plays document the many Henrys of the Tudor line, from Henry IV to Henry VIII.

In countries without monarchies, families who pass down names also may choose to use a Roman numeral to distinguish generations. But a more recognizable modern use is in sporting events. The final game of the 2025-2026 NFL season will be Super Bowl LX, which translates to Super Bowl 60. The Winter 2026 Olympics will be the XXV Olympiad, or the 25th Games.