Roman Numeral — XXXI (31) — free printable diagram

What is XXXI in Roman numerals?

XXXI is the Roman numeral for 31 — thirty-one. Written the other way round, 31 in Roman numerals is XXXI.

Roman numeral

XXXI

Number

31

In words

thirty-one

Symbols used

I = 1, X = 10

Written as

X (10) + X (10) + X (10) + I (1)

• XXXI is built from X (10) + X (10) + X (10) + I (1), which adds up to 31.
• Roman numerals are read from left to right, adding each symbol as you go, except where the subtraction rule applies.