What is the Roman numeral for 500?

The story behind the answer

D is the Roman numeral for 500. By contrast, C = 100, X = 10, and L = 50. Roman numerals use specific letters to represent set values and combine them additively or subtractively to form numbers.

Historically, D likely evolved from a halved form of the symbol for 1000 (M), which was once written as IƆ; the right half simplified into D for 500. To remember the order of values, use the sequence I, V, X, L, C, D, M (1, 5, 10, 50, 100, 500, 1000). A handy mnemonic is “I Value Xylophones Like Cows Do Milk,” which helps fix D as 500 in the progression.