Roman Numerals Guide

Everything about Roman numerals in one place. Roman numerals are the number system of ancient Rome — seven letters (I, V, X, L, C, D, M) that still show up on clocks, book chapters, movie credits and tattooed dates. This guide collects our full walkthrough, from first principles to specialized uses.

The seven letters at a glance

LetterValueLetterValue
I1L50
V5C100
X10D500
M1000

Combine them by three rules — repeat at most three times, subtract with exactly six pairs (IV, IX, XL, XC, CD, CM), and write large-to-small. 2026 is MMXXVI; 49 is XLIX, never IL.

Start here

Type and convert

Dates, years and tattoos

Where to go next

New to the system? Read what Roman numerals are first, then keep the 1-100 chart bookmarked. Converting a specific date or year? Jump straight to the date guide or the converter.