Roman Numerals: A Quick Reference

Roman numerals still appear on clocks, book chapters, movie credits, and outlines. They use seven letters, each with a fixed value, and combine left to right with a few subtraction rules. I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000 ### Subtraction rule A smaller nume

Published June 8, 2026

Roman numerals still appear on clocks, book chapters, movie credits, and outlines. They use seven letters, each with a fixed value, and combine left to right with a few subtraction rules.

Letter values

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000

Subtraction rule

A smaller numeral before a larger one subtracts: IV = 4, IX = 9, XL = 40, CM = 900.

No more than three repeats

III is 3; 4 is IV, not IIII (except on some clock faces).

Common examples

XIV = 14 (10 + 4) XLIX = 49 (40 + 9) MCMXC = 1990 (1000 + 900 + 90)

Reading tip

Scan from left to right: add when the next symbol is smaller or equal, subtract when it is larger.