Roman Numeral Converter

Convert any number from 1 to 3999 into Roman numerals and back — years, chapter numbers, Super Bowl numbers, or a full birthday date in the dotted tattoo format. Invalid numerals like IIII or VX are caught and explained.

Quick years:

2026 in Roman numerals is

MMXXVI

📌 Uses standard subtractive notation: 4 = IV, 9 = IX, 40 = XL, 90 = XC, 400 = CD, 900 = CM. Numerals like IIII or VX are rejected as invalid.
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Roman numerals chart

1–20

NumberRoman
1I
2II
3III
4IV
5V
6VI
7VII
8VIII
9IX
10X
11XI
12XII
13XIII
14XIV
15XV
16XVI
17XVII
18XVIII
19XIX
20XX

Tens: 30–100

NumberRoman
30XXX
40XL
50L
60LX
70LXX
80LXXX
90XC
100C

Hundreds: 200–1000

NumberRoman
200CC
300CCC
400CD
500D
600DC
700DCC
800DCCC
900CM
1000M

The subtractive rule: why 4 is IV, not IIII

Roman numerals are mostly additive — you write symbols from largest to smallest and add them up, so LXXVI is 50 + 10 + 10 + 5 + 1 = 76. The exception is the subtractive rule: a smaller symbol placed before a larger one is subtracted. Only six such pairs are allowed: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). That is why 1999 is MCMXCIX and not something shorter like MIM — I can only be subtracted from V or X, never from M. It also caps repetition: you never write the same letter four times in a row, so IIII and combinations like VX are invalid in standard notation.

No zero, and the clock-face exception

Two famous quirks. First, there is no Roman numeral for zero: the system has no place value, so it never needed an empty-position digit — Romans simply wrote the word "nulla" when they meant nothing. Second, traditional clock faces break the subtractive rule on purpose and show 4 as IIII. The usual explanations are visual symmetry with VIII on the opposite side of the dial and easier reading at odd angles. It is a centuries-old design convention you will find on everything from Big Ben-era tower clocks to modern luxury watches.

Dates in Roman numerals — the tattoo format

The most popular modern use of Roman numerals is writing a meaningful date — a birthday, wedding, or anniversary — with each part converted separately and joined by interpuncts. December 25, 1998 becomes XII·XXV·MCMXCVIII. The "Birthday / date to Roman" tab in the converter produces exactly this format so you can copy it straight into a design. Since tattoos are permanent, double-check by converting the result back to numbers before you commit.

More text & number tools

Encode text instead of numbers with the Morse code translator or the binary translator. For switching numbers between binary, decimal, and hexadecimal, use the number base converter, and check text lengths with the character counter.

Frequently asked questions