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Convert Roman numerals to numbers and numbers to Roman numerals in seconds. Enter a number to get the Roman form, or paste a Roman numeral to see its Arabic (standard) value.
This converter supports values from 1 to 3,999,999.
What are Roman numerals?
Roman numerals are an old number system from ancient Rome. Instead of digits, they use letters to represent values. You still see them today on clocks, book chapters, movie titles, and event names.
Roman numeral letters used here: I, V, X, L, C, D, M
How to use the converter
- Number to Roman numeral: Enter any number from 1 to 3,999,999.
- Roman numeral to number: Enter a Roman numeral like XIV, MMXXV, or _X (see the overline rule below).
Big numbers (overline rule)
Roman numerals above 3,999 can use an overline (a line over the numeral). An overline means the value is multiplied by 1,000.
Since overlines are hard to type, this tool uses an underscore:
Type _ before a letter to mean it has an overline.
Examples
_C = 100,000
_C_M = 900,000
Roman numerals chart
| Roman numeral | Value | Calculator input |
| I | 1 | I |
| V | 5 | V |
| X | 10 | X |
| L | 50 | L |
| C | 100 | C |
| D | 500 | D |
| M | 1,000 | M |
| I̅ | 1,000 | _I |
| V̅ | 5,000 | _V |
| X̅ | 10,000 | _X |
| L̅ | 50,000 | _L |
| C̅ | 100,000 | _C |
| D̅ | 500,000 | _D |
| M̅ | 1,000,000 | _M |
Largest standard Roman numeral
Without overlines, the largest number normally written in Roman numerals is:
3,999 = MMMCMXCIX
To write bigger numbers, Roman numerals use overlines.
Example: writing 50,000
L equals 50. With an overline, it becomes 50,000.
L̅ = 50 × 1,000 = 50,000
Example 1: Number to Roman numeral
Input: 49
Output: XLIX
Explanation: XL is 40 (50 minus 10). IX is 9 (10 minus 1). 40 + 9 = 49.
Example 2: Roman numeral to number
Input: CDXLIV
Output: 444
Explanation: CD is 400, XL is 40, IV is 4. 400 + 40 + 4 = 444.
Example 3: Big number to Roman numeral (overline input)
Input: 50,000
Output: _L
Explanation: L is 50. Overline means × 1,000. This tool types the overline as _.
Example 4: Overline Roman numeral to number
Input: _XIV
Output: 14,000
Explanation: XIV is 14. Overline means × 1,000. 14 × 1,000 = 14,000.
More Roman Numerals Converter Tools
- Roman Numeral Date Converter: Change any date into Roman numerals. Or type Roman numerals to get the date in normal numbers.
API Documentation Coming Soon
Documentation for this tool is being prepared. Please check back later or visit our full API documentation.
