In the decimal system, Roman numerals represent numbers in the decimal system, but they cannot be used for mathematical operations.
Symbols are used to represent different numbers, with I representing 1, V representing 5, X representing 10, L representing 50, C representing 100, D representing 500, and M representing 1,000.
Roman numeral symbols are listed below:
| 1 | 5 | 10 | 50 | 100 | 500 | 1,000 |
|---|---|---|---|---|---|---|
| I | V | X | L | C | D | M |
The value of a numeral is determined by its position in relation to other symbols. When a symbol of equal or lesser value is placed after another symbol, their values are added. However, if a lesser value symbol is positioned before another symbol, its value is reduced.
VI, or 6, would be read as “five plus one” (5 + 1), and XI, or 11, as “ten plus one” (10 + 1).
The Roman numeral IV, or 4, would be read as “one less than 5” (5 – 1). Likewise, the Roman numeral IX, or 9, would be read as “one less than 10” (10 – 1).
Here is a table of numbers and their Roman numeral equivalents, followed by a more detailed explanation of how to convert them. Just scroll through the table or use Ctrl/Cmd + F to find what you need:
| NUMBER | ROMAN NUMERAL |
|---|---|
| 1 | I |
| 2 | II |
| 3 | III |
| 4 | IV |
| 5 | V |
| 6 | VI |
| 7 | VII |
| 8 | VIII |
| 9 | IX |
| 10 | X |
| 11 | XI |
| 12 | XII |
| 13 | XIII |
| 14 | XIV |
| 15 | XV |
| 16 | XVI |
| 17 | XVII |
| 18 | XVIII |
| 19 | XIX |
| 20 | XX |
| 21 | XXI |
| 22 | XXII |
| 23 | XXIII |
| 24 | XXIV |
| 25 | XXV |
| 30 | XXX |
| 40 | XL |
| 50 | L |
| 60 | LX |
| 70 | LXX |
| 80 | LXXX |
| 90 | XC |
| 100 | C |
| 101 | CI |
| 102 | CII |
| 103 | CIII |
| 104 | CIV |
| 105 | CV |
| 200 | CC |
| 300 | CCC |
| 400 | CD |
| 500 | D |
| 600 | DC |
| 700 | DCC |
| 800 | DCCC |
| 900 | CM |
| 1,000 | M |
| 1,001 | MI |
| 1,002 | MII |
| 1,003 | MIII |
| 1,004 | MIV |
| 1,005 | MV |
| 1,900 | MCM |
| 2,000 | MM |
| 3,000 | MMM |
| 3,999 | MMMCMXCIX |
How to Convert a Number into Roman Numerals
Divide the number you’re converting into groups of thousands, hundreds, tens, and ones, and convert each group separately.
To convert 2,014 (the year freeCodeCamp was founded) into Roman numerals, follow these steps:
2,014 = 2,000 + 10 + 4Once each group has been converted, combine them to get the Roman numeral equivalent:
* 2,000 = MM
* 10 = X
* 4 = IV
2,014 = 2,000 + 10 + 4 = MMXIVHow to Represent Large Numbers in Roman Numerals
There is only a range of 1 to 3,999 in the chart above.
Since 4 and 9 are represented in a different way, this is the case. As you can see from the table above, whenever a 4 or 9 appears (including 40, 90, 400, 900), the Roman numerals are arranged in such a way that they immediately subtract the lesser symbol from the greater one.
Due to the fact that Roman numerals were never fully standardized, the number 4,000 might appear as MMMM.
Since 4 (and 9) have special representations in lower numbers, many consider this invalid.
A vinculum, or a horizontal line above one or more symbols, is a common way to represent larger Roman numerals.
You can multiply a Roman numeral symbol by 1,000 if it has a horizontal line over it.
Roman numeral symbols with the vinculum are as follows:
| 1,000 | 5,000 | 10,000 | 50,000 | 100,000 | 500,000 | 1,000,000 |
|---|---|---|---|---|---|---|
| M or I | V | X | L | C | D | M |
Roman numeral symbols, 4,000 would be represented as the following:
IV
To get you started, here is a table of larger numbers and their Roman numeral representations:
| NUMBER | ROMAN NUMERAL |
|---|---|
| 4,000 | IV |
| 4,001 | IVI |
| 4,002 | IVII |
| 4,003 | IVIII |
| 5,000 | V |
| 6,000 | VI |
| 7,000 | VII |
| 8,000 | VIII |
| 9,000 | IX |
| 10,000 | X |
| 40,000 | XL |
| 90,000 | XC |
| 400,000 | CD |
| 900,000 | CM |
| 1,000,000 | M |
In HTML and CSS, you can add a vinculum or horizontal line over Roman numerals
To add a vinculum to Roman numerals online, wrap the symbols in an element and use CSS.
You can add a horizontal line over the symbol IV in IVIII by wrapping it in a span element and setting its text-decoration property to overline:
<p><span style="text-decoration: overline;">IV</span>III</p>Which will render the following:
IVIII
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