31 in Roman numerals is XXXI, built from XXX + I (XXX = 30, I = 1), which add up to 31.
How 31 is written in Roman numerals
The number 31 is written XXXI in Roman numerals. Roman numerals use seven letters — I (1), V (5), X (10), L (50), C (100), D (500) and M (1000) — combined from largest to smallest, with subtractive pairs such as IV (4) and IX (9). Need another number? Use the Roman numeral converter or see the 1–100 chart.
Building XXXI step by step — take the largest value that fits, write its symbol, subtract, repeat.
| Write | Value | Remaining before | Remaining after |
|---|
| X | 10 | 31 | 21 |
| X | 10 | 21 | 11 |
| X | 10 | 11 | 1 |
| I | 1 | 1 | 0 |
Where you see XXXI
The 31st Super Bowl was Super Bowl XXXI; the NFL has used Roman numerals for every edition except Super Bowl 50.
Nearby numbers
Popular numbers in Roman numerals
Frequently Asked Questions
What is 31 in Roman numerals?
31 in Roman numerals is XXXI. Reading it left to right gives X (10) + X (10) + X (10) + I (1) = 31. The number below it, 30, is written XXX, and the number above it, 32, is written XXXII.
How do you write 31 in Roman numerals?
Write 31 as XXXI, combining X (10) + X (10) + X (10) + I (1). Roman numerals are built by taking the largest value that still fits, writing its symbol and subtracting it, which reduces 31 in 4 steps: X leaves 21, X leaves 11, X leaves 1, I leaves 0. Every symbol keeps the same value wherever it stands, so the order is fixed and XXXI is the only standard spelling of 31.
Which letters make up XXXI?
XXXI is made up of X three times and I once. X is worth 10 and I is worth 1. Added together those values come to 31, because Roman numerals are read by summing the symbols from left to right.
How is XXXI read out loud?
XXXI is read as the number it stands for, thirty-one, and never letter by letter. Roman numerals are a way of writing values rather than a separate set of names, so the spoken form is the same whether the page shows 31 or XXXI. A chapter or volume numbered XXXI, for instance, is simply chapter thirty-one.