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Roman Numerals Reference

The seven letters that write numbers the Roman way, with the subtractive pairs and the values you actually meet in the wild.

At a glance

Key facts
Symbols

I, V, X, L, C, D, M

Subtractive

IV, IX, XL, XC, CD, CM

Repeats

Three of a kind at most

Still used

Clocks, chapters, dates

Symbols and common values

15 rows
NumeralValue
I1
IV4
V5
IX9
X10
XL40
L50
XC90
C100
CD400
D500
CM900
M1000
MCMXCIV1994
MMXXVI2026

Where it comes from

Roman numerals grew out of tally marks in ancient Italy and were the everyday number system of the Roman world. The modern form uses seven letters: I, V, X, L, C, D, and M, combined by addition, with the later subtractive convention (IV for 4, IX for 9) becoming standard in the Middle Ages. The system survives today on clock faces, in book chapters and movie sequels, on monuments, and in the regnal numbers of monarchs and popes.

How to use it

Read left to right and add the values, except when a smaller symbol sits directly before a larger one, in which case you subtract it. Only six subtractive pairs are used: IV and IX, XL and XC, CD and CM. A symbol never repeats more than three times in a row, which is exactly why the subtractive pairs exist: 40 is XL, not XXXX. To decode a long numeral, split it into thousands, hundreds, tens, and units. MMXXVI is MM (2000), XX (20), VI (6), so 2026.

This page is a standing reference at a fixed URL, built to be linked and cited. The data here is compiled from the standard subtractive Roman numeral notation in modern use.

See also