About this tool
Converts numbers to Roman numerals (1 to 3999) and Roman numerals back to numbers. Useful for dates on monuments and clocks, book chapters and volumes, royal and papal successions, movie copyright lines, and any formal or classical context where Roman numerals are preferred to Arabic.
How to use
- Pick the conversion direction.
- Enter the number (between 1 and 3999) or the Roman numeral.
- The result appears automatically.
Frequently asked questions
- Why the 3999 limit?
- The standard Roman system only uses symbols up to M (1000). For numbers larger than 3999, additional symbols would be needed (like a horizontal bar over a letter to multiply by 1000), which are neither standard nor widely recognised. For most modern uses, the 1 to 3999 range is enough.
- Did the Romans have zero?
- No. The concept of zero as a number was formalised later, coming from Indian mathematics. Romans represented absence with the word "nulla" (nothing) but had no numeral for zero. That's why this tool starts at 1.
- What rules do Roman numerals follow?
- Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. They add to the left when greater or equal (VII = 7) and subtract when smaller before a larger one (IV = 4). They can't repeat more than three times in a row (4 is IV, not IIII). Some historical forms use IIII on clocks, but the modern rule favours IV.