What are Roman numerals?
Roman numerals are a number-writing system that originated in ancient Rome. Instead of using the digits 0–9 in a positional decimal system, Roman numerals combine letters to represent numerical values.
The seven main symbols are I, V, X, L, C, D and M. These symbols represent 1, 5, 10, 50, 100, 500 and 1000.
Roman numerals are still used for book chapters, clock faces, monarch names, film credits, events and decorative numbering.
Convert ordinary whole numbers into standard Roman numeral notation.
Find the integer value represented by a valid Roman numeral.
The converter supports the conventional notation used for numbers up to 3999.
Roman numeral chart: I, V, X, L, C, D, M
| Roman numeral | Number |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
How to use the Roman numeral converter
- Enter your value. Type an integer from 1 to 3999, or a Roman numeral such as XIV.
- Calculate. Select the Calculate button.
- Read the result. The tool displays the corresponding integer and Roman numeral.
- Copy or save. Use the available result controls if you need a record.
Roman numeral conversion rules
Roman numeral conversion follows a combination of addition and subtraction. The order of the symbols determines their combined value.
Addition rule
When symbols appear in descending order, their values are generally added.
VIII = V + I + I + I
5 + 1 + 1 + 1 = 8
VIII = 8
Subtraction rule
A smaller symbol placed immediately before certain larger symbols indicates subtraction.
| Subtractive pair | Value |
|---|---|
| IV | 4 |
| IX | 9 |
| XL | 40 |
| XC | 90 |
| CD | 400 |
| CM | 900 |
Only these six subtractive pairs are used in the conventional Roman numeral system supported by this converter.
Repetition rule
The symbols I, X, C and M may be repeated up to three times consecutively in standard notation.
V, L and D are not repeated in conventional Roman numerals.
Worked example: Convert 2026 to Roman numerals
Step 1: Break 2026 into place values
2026 = 2000 + 20 + 6
Step 2: Convert each part
- 2000 = MM
- 20 = XX
- 6 = VI
Step 3: Combine the symbols
MM + XX + VI = MMXXVI
Result: 2026 = MMXXVI
Worked example: Convert MCMXCIV to a number
Break MCMXCIV into standard groups:
- M = 1000
- CM = 900
- XC = 90
- IV = 4
1000 + 900 + 90 + 4 = 1994
Result: MCMXCIV = 1994
Roman numerals 1 to 20
| Number | Roman numeral | Number | Roman numeral |
|---|---|---|---|
| 1 | I | 11 | XI |
| 2 | II | 12 | XII |
| 3 | III | 13 | XIII |
| 4 | IV | 14 | XIV |
| 5 | V | 15 | XV |
| 6 | VI | 16 | XVI |
| 7 | VII | 17 | XVII |
| 8 | VIII | 18 | XVIII |
| 9 | IX | 19 | XIX |
| 10 | X | 20 | XX |
Common Roman numeral values
| Number | Roman numeral |
|---|---|
| 40 | XL |
| 49 | XLIX |
| 50 | L |
| 90 | XC |
| 99 | XCIX |
| 100 | C |
| 400 | CD |
| 500 | D |
| 900 | CM |
| 1000 | M |
| 1999 | MCMXCIX |
| 2024 | MMXXIV |
| 2025 | MMXXV |
| 2026 | MMXXVI |
| 3999 | MMMCMXCIX |
Why does this converter support only 1–3999?
The conventional Roman numeral system commonly taught today uses symbols from I through M and standard subtractive notation.
Larger numbers can be represented using extended conventions, including overlines and other historical notations.
However, these extensions are not universally standardized in the same way as the common 1–3999 notation.
The number zero does not have a standard representation in the conventional Roman numeral system used by this calculator.
Common invalid Roman numeral examples
| Invalid form | Correct form | Number |
|---|---|---|
| IIII | IV | 4 |
| VIIII | IX | 9 |
| XXXX | XL | 40 |
| IC | XCIX | 99 |
| IL | XLIX | 49 |
| VV | X | 10 |
These examples are considered invalid under the conventional notation used by this calculator. Some historical writing systems and clock designs use alternative forms.
Where are Roman numerals used today?
- Clock faces and decorative watches.
- Book chapters and introductory sections.
- Names of monarchs and popes.
- Movie copyright years and credits.
- Sporting events such as Super Bowl numbering.
- Historical inscriptions and monuments.
Frequently asked questions
What is 2026 in Roman numerals?
2026 is MMXXVI. MM represents 2000, XX represents 20 and VI represents 6.
What is 2025 in Roman numerals?
2025 is MMXXV.
What is 1000 in Roman numerals?
1000 is represented by M.
What is 50 in Roman numerals?
50 is represented by L.
What is 49 in Roman numerals?
49 is XLIX. XL represents 40 and IX represents 9.
What is the Roman numeral for zero?
There is no standard symbol for zero in the conventional Roman numeral system used by this converter.
What is the largest number supported?
The converter supports integers from 1 to 3999. The standard representation of 3999 is MMMCMXCIX.
Can I enter Roman numerals instead of numbers?
Yes. Enter a standard Roman numeral such as XIV or MMXXVI to calculate its integer value.
Are Roman numerals case-sensitive?
Roman numerals are conventionally written in uppercase. Enter uppercase symbols for the most predictable results.
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