Roman Numeral Converter
Convert numbers to Roman numerals and back, up to 3,999,999, or convert a date or list of numbers at once.
Change the values and press Calculate to work out your own figures.
Number ⇄ Roman numeral
Enter a number or a Roman numeral; it converts the other way.
Show the working
- 2,026 = 1,000 + 1,000 + 10 + 10 + 5 + 1
- = M + M + X + X + V + I = MMXXVI
Dates and lists
Enter a date or several numbers or numerals separated by -, ., /, \, | or spaces.
| Given | Converted |
|---|---|
| 9 | IX |
| 26 | XXVI |
| 2026 | MMXXVI |
Show the working
- 9 = IX
- 26 = XXVI
- 2026 = MMXXVI
How to use it
Enter a number or a Roman numeral; it converts the other way. Enter a date or several numbers or numerals separated by -, ., /, \, | or spaces.
Letters stand for digits above 9 (A = 10 … Z = 35) and can be typed in either case; prefixes such as 0b and 0x, spaces and underscores are ignored. Show the working gives each step.
Key facts
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000 Subtractive pairs: IV 4, IX 9, XL 40, XC 90, CD 400, CM 900
Reading Roman numerals
Add the letters from left to right, largest first; a smaller letter written before a larger one is subtracted, but only in the six pairs IV, IX, XL, XC, CD and CM. So 1990 is M + CM + XC = MCMXC.
Large numbers
The Romans marked thousands with a bar over the letters: V̅ is 5,000 and M̅ is 1,000,000.
Questions
What is 2026 in Roman numerals?
MMXXVI.
Why do clocks show IIII?
It is a long-standing clock-face tradition; the standard form is IV. The converter reads both.
Formulas
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000 Subtractive pairs: IV 4, IX 9, XL 40, XC 90, CD 400, CM 900
Sources
Limitations
- Numbers have at most 1,000 characters; Roman numerals cover whole numbers from 1 to 3,999,999.