A Guide to Roman Numerals in Essays

The Romans gave us many things: roads, sanitation, towns, the calendar… and numerals! Okay, not the numerals we use on a daily basis (we have ancient Arabic mathematicians to thank for those). Instead, they gave us Roman numerals.

So, how are these numerals different? How do they work? And should you use them in academic writing? This post will answer all of your questions.

What Are Roman Numerals?

Roman numerals are indicated using letters (not the ‘numbers’ we usually think of). These can be written as either capitals or lower-case letters. The symbols have the following values:

You can then combine these to make other numbers. For example, the number eight would be written as ‘VIII’ (one ‘five’ plus three ‘ones’). Similarly, 25 would be written as ‘XXV’ (two ‘tens’ plus one ‘five’).

When a number would require four of one symbol in succession, the Roman numeral is worked out by subtracting from the next step up. For instance:

• I before V or X = minus 1 (e.g. IV = 4 and IX = 9)
• X before L or C = minus 10 (e.g. XL = 40 and XC = 90)
• C before D or M = minus 100 (e.g. CD = 400 and CM = 900)

This system only works up to 3,999, with larger numbers indicated by placing a line over another symbol (see below). This line indicates that the numbers are multiplied by 1,000, so a ‘V’ with a line over it equals 5,000. However, it is unusual to write large numbers with Roman numerals.

If you struggle to work out a numeral for a specific value, you can use an online convertor tool.

Where Are Roman Numerals Used?

Although we don’t use Roman numerals for counting, they are still used for other reasons. Some common situations where you’ll see Roman numerals used in the modern world include:

• Titles of monarchs (e.g. Queen Elizabeth II)
• Chapter numbers in books or section numbers in plays
• Page numbering for prefaces and other introductory material in a book
• The year of production for films and television shows (e.g. MCMLXXXVI = 1986)
• Film sequels (e.g. Star Trek V: The Final Frontier)
• Sporting events (e.g. Super Bowl XXXIX)
• Numbering items in a list

Roman Numerals in Essays

Like any numbers in an essay, there are rules about when Roman numerals should be used. This is largely restricted to subdivisions in plays and books, lists, and titles of monarchs.

In most other situations, it is better to use words or Arabic numerals. This is true even if the number is given in Roman numerals elsewhere (e.g. the year a film was released).

However, Roman numerals are common in alphanumeric outlines. You can use these to set out a process or the structure of something. Capitalised Roman numerals are typically used for the main divisions in these lists, with lower case numerals sometimes used for subsequent subdivisions:

If you need to use an alphanumeric outline in your work, this is the standard format.